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Stress itself is not an illness. Stress is a healthy reaction of the organism to cope with increased demands (stressors). Stress causes physical, psychological and neurological changes and, as a result, reinforces evolutionary selection.1
ADHD mediates its symptoms - probably rather coincidentally - via the same neurotransmitter shifts as severe stress. Many stress symptoms therefore coincide with ADHD symptoms, although ADHD has a completely different cause than stress. Stress symptoms go with the stressor, ADHD stays. ADHD, even if it is purely genetic, can be the result of a permanent overactivation of the HPA axis (stress axis), as the animal model of SHR shows. However, there are many different causes of ADHD, so it is not permissible to equate ADHD and stress.
Extreme, unmanageable, uncontrollable stress changes the way we feel and think in order to achieve optimal problem solving. These specific changes can be useful for coping with increased demands. We call this Stress benefits.
Stress can have positive effects on the body, such as an increased heart rate to increase physical performance or an inhibition of inflammation to optimize the ability to act in the short term. Existing neural connections in the brain can be broken down more easily to make room for new and better models that are more effective in coping with a stressful situation or that help to avoid getting into such a threatening situation again.
Examples of stress benefits in situations where stressors threaten survival:
Hyperactivity can be helpful during fight or flight.
Distractibility (which usually occurs during preoccupation with intrinsically less important things) enables increased alertness to danger and a faster response to it.
Task switching problems (which usually occur when dealing with intrinsically important things) result in less distractibility.
Delay aversion and procrastination help us to focus on combating stressors and put less intrinsically important things on the back burner.
Dysphoria during inactivity, a deterioration in mood when resting, motivates the person affected to remain active and combat the stressor.
Lack of drive lowers the drive for activities that do not serve to cope with stress, while the drive for stress-relevant activities is increased.
Brooding can be a functional mechanism as long as constructive solutions are sought.
Dysphoria, listlessness, inner restlessness and inability to enjoy life have the benefit of keeping the focus on the stressor and thus increasing the probability of survival.
Mood swings, aggression and anxiety serve to adapt to different stressors.
Frustration intolerance motivates people to find alternative solution strategies.
Rejection Sensitivity and Tend and Befriend serve to bind us to the group, which was very important in the millions of years when humans lived in small groups as nomads.
Self-esteem problems promote change and self-improvement to cope with stress.
Anxiety increases caution.
Inner emptiness promotes a focus on the stressor.
Decreased empathy can promote selfish behavior, while increased empathy strengthens the group bond.
Novelty Seeking could seek new ways of coping with stress.
Organizational difficulties and the inability to keep appointments can be consequences of the stress of tackling priority problems.
The shift in behavioral control from the slow but precise PFC to fast but imprecise posterior and subcortical brain regions serves to enable rapid action in survival-threatening situations2 and is triggered by very high dopamine and noradrenaline and/or glucocorticoid levels during acute severe stress. In ADHD, there is a similar impairment of the working memory located in the dorsolateral PFC - however, not as a result of high dopamine or noradrenaline levels due to severe acute stress, but in ADHD due to an underactivation of the PFC as a result of reduced dopamine levels. Reduced dopamine levels in the PFC can be caused by genetic constellations (as is usually the case with ADHD) or be the result of chronic stress.3 The deactivation of the PFC and the impairment of working memory lead to similar symptoms if dopamine levels are too high or too low (extracellular), as the brain only functions optimally at medium dopamine and noradrenaline levels.
Not all stress/ADHD symptoms have a direct stress benefit themselves. Some are merely nature’s accepted consequences of the stress benefits of other symptoms, which are so beneficial that the associated disadvantages are outweighed. Otherwise, these stress symptoms would probably have disappeared long ago due to a lack of sufficient stress benefits.
In contrast, symptoms of other mental disorders are often dysfunctional because they offer no immediate benefit.
Depression, for example, cannot help to combat the stressor. It is doubtful whether accepting the loss could be functionally useful in order to avoid unnecessary energy loss. Lack of drive and hopelessness, symptoms of depression, do not help to combat a stressor.
An anxiety disorder leads to an inability to act because the increased caution is overly intense. In the case of obsessive-compulsive disorder, the increased care becomes dysfunctional.
The physical changes increase the ability to fight and flee.
Some examples:
Increased heart rate:
increased supply of oxygen-rich blood to the organs to increase physical performance
Constriction of the peripheral blood vessels (turning pale):
Blood is drawn into the body. Protection against bleeding to death in the event of injuries caused by fight or flight
Increased activity of the liver:
more glucose in the blood, increased short-term energy availability
Inhibition of inflammation:
reduced energy expenditure for the immune system by suppressing its activity, which brings advantages for the desired short-term optimization of the ability to act.
With long-term stress, however, this weakening of the immune system has a detrimental effect and can even lead to death in extreme cases4
Reduced sex drive; in extreme cases: infertility.
In life-threatening situations, pregnancy would be a considerable additional burden.
This also promotes evolution from the point of view of the species: stress inhibits the reproduction of those individuals that are not optimally adapted to the environmental conditions4
Muscle tension
Pretensioning the muscles protects against injury in the event of a possible fight or flight.
The brain is constantly being changed by positive and negative experiences (neuroplasticity). Neuroplasticity does not end when we grow up, but it does decrease. Neuroplasticity is a basic prerequisite for learning.
Mild / controllable stress strengthens the existing neuronal connections, as they have proven their competence by successfully mastering the task.5
Strong / uncontrollable stress, on the other hand, supports the dissolution of existing neural connections in the brain in order to make room for newer, better models, as the problem-solving models represented in the previous connections have not proven to be optimal for avoiding the current (in extreme cases: survival-threatening) stress situation.
Many people know that certain of their habits are dysfunctional and yet are unable to change them. After a drastic experience (uncontrollable stress), they are suddenly able to change their habits.
Stressors that are too intense, too frequent and occur for too long damage the stress response systems. In the first years of life, while the brain’s neurotransmitter systems are developing and seeking an appropriate balance for the respective neurotransmitters, the stress response systems are particularly vulnerable. Certain genetic dispositions can further increase this vulnerability. ⇒ How does ADHD develop? Genes + environment
Details
Neural plasticity is mediated by the adaptation of neurochemical, neuroanatomical and behavioral systems. The endocrine system acts as a signaling network that triggers chemical and morphological changes in certain neurons and glial cells. The hippocampus (which controls learning and memory processes) responds to glucocorticoids during the diurnal cycle and in response to stress (cortisol binds to glucocorticoid receptors) as well as to vasopressin.
Noradrenaline-stimulated cyclic AMP accumulation, an index of reduced noradrenaline sensitivity due to prolonged stress, is increased by removal or blockade of the adrenal gland, where cortisol and other stress hormones are produced, while cortisol or ACTH are reduced.6
Slightly increased levels of glucocorticoids (cortisol) as a result of positive experiences (including successfully overcoming a challenge) promote the growth of nerve cells, while greatly increased levels of glucocorticoids inhibit this.789
In contrast, intense negative experiences, especially stressful situations that cannot be managed, weaken the previous circuitry in the brain and support its breakdown. As the previous circuitry was obviously not sufficiently suitable for coping with the situation, but allowed the individual to get into an unmanageable (potentially dangerous) situation, it makes sense to weaken it and stimulate the growth of new, better pathways and circuitry.7
Stress causes very typical psychological symptoms. In our opinion, almost all ADHD symptoms are functional stress symptoms. (⇒ ADHD symptoms are stress symptoms). For several million years, these symptoms have had direct benefits for the survival of the individual and thus its species.
Let’s say one of our ancestors was faced with a potentially life-threatening situation. Be it a sabre-toothed tiger that doesn’t look like it’s dragging itself sluggishly into the shadows from a sumptuous meal, or a group of warriors from an unknown or even hostile tribe approaching at a run.
Now the poor guy already has enough problems on his hands - what use are stress symptoms to our ancestor? What advantage do they have?
We no longer live in the savannah, no longer have to hunt for our food and have outsourced protection from predators or warriors to the police and army. But our stress systems are millions of years old and were very, very successful for a very long time. They are therefore deeply rooted and it will take a correspondingly long time for them to give way to newer stress reactions that are more adapted to modern life. If we take a look at the ancient living conditions that have existed since the beginning of hominids, this leads to a profound understanding of the original benefits of stress symptoms.
Stress benefits are not the result of cognitive deliberation that the person concerned or the stress response system have done in advance in a quiet chamber in order to implement them in due course. We consider stress benefits to be successful reaction patterns that have evolved in evolutionary biology. The individuals with these response patterns are the descendants of those who developed these patterns by chance and for whom these patterns successfully helped them to survive. Therefore, they were more likely to be present in subsequent generations than other behavioral and response patterns that were not as beneficial for survival.
Functional stress symptoms are reactions and behavioral patterns that are helpful in extreme situations in order to increase the probability of survival.
The conclusion must then be that stress symptoms are initially completely healthy neurophysiological reactions. ADHD symptoms, on the other hand, are not, although they are identical: because ADHD triggers these symptoms without an adequate stressor being present.
However, this explains why any attempt to understand the neurophysiological development of ADHD symptoms as a part of the disease must fail. If the development of an ADHD symptom were to be interrupted at its neurophysiological point of origin, this would also prevent healthy stress symptoms, which are a functional reaction to a stressor.
Increased physical activity and a willingness to be active is helpful and conducive to survival during fight or flight.
Hyperactivity occurs mainly in children and adolescents and subsides in adulthood. This could indicate a particular advantage in escape.
In addition to this stress benefit, hyperactivity acts as a stress reduction tool:
Hyperactivity can also be observed in animals as an act of jumping during uncontrollable stress (with increased cortisol blood levels), whereby these acts of jumping also measurably serve to reduce stress (reduction of stress levels).1011
In adults, hyperactivity is most noticeable as constantly repetitive micro-movements: foot tapping, finger tapping, etc. These constantly repeated movements have a certain similarity to stereotypies or tics, which also have a stress-relieving effect as skipping actions.1211
4.1.1. Fine motor problems as a consequence of stress¶
From the perspective of movement optimization, a deterioration in gross and fine motor skills is not plausible. Especially in combat situations, at least gross motor skills are important.
Under stress, the reaction speed is increased. This is at the expense of the accuracy of motor actions. In this respect, the deterioration in fine motor skills is not a stress benefit, but a (detrimental) consequence of another stress benefit, namely the increase in reaction speed.
4.2. Stress benefits of inhibition problems / impulse control problems¶
Spontaneous, ill-considered decisions do not initially appear to be an appropriate response to a stressor. The less time is spent on decision-making, the greater the risk of wrong decisions. However, impulsiveness can also be seen as an urgency to make decisions13
Noradrenaline is the primary stress hormone of the central nervous system (the brain). A slightly increased norepinephrine level, as occurs during controllable stress, stimulates the PFC to increased activity. Only a very high noradrenaline level, as occurs in the case of uncontrollable stress, switches off the PFC14 and activates the stress axis (HPA axis), at the end of which cortisol is released. To ensure that the deactivation of the PFC does not remain a permanent state, cortisol causes noradrenaline to be reduced again at the end.
One cause of ADHD-HI can be a permanent overactivation of the HPA axis (e.g. in the most commonly used ADHD animal model, the SHR), because an insufficient endocrine stress response does not shut down the PFC and the HPA axis. Dexamethasone shuts down the HPA axis and eliminates ADHD symptoms as well as hypertension in SHR. The particular high endocrine stress response could explain the ADHD-I presentation form (and possibly SCT given the symptomatology) with too frequent shutdown of the PFC and HPA axis.
On the other hand, under extreme stress - in fight or flight - it is sometimes simply necessary for survival to make decisions very quickly.we are the descendants of those who were at least not the slowest at hitting or running away. We have inherited from the winners (the survivors) their stress response that extreme stress turns off the PFC because faster reactions are advantageous in fight or flight.
If you suddenly find yourself confronted by a hungry lion in the savannah, you should decide as quickly as possible which way to run. In the race to be the second slowest at best, the younger parts of the brain (especially the PFC), which are optimized for the careful analytical consideration of problems, are more of a hindrance - because they analyze very, very slowly. Fast, spontaneous (but inaccurate) decisions have always been made by the older (and smaller) parts of the brain in the limbic system (amygdala, hippocampus).
However, this is probably not due to advantages in energy consumption. The energy consumption of the brain in both resting and alert states is almost the same. Whether it is therefore a survival advantage to shut down the new parts of the brain, which are of little help in such emergency situations (because they are too slow), in order to save energy is questionable. The brain, which accounts for 2% of body weight and contains less than 1 per thousand of the body’s cells, consumes around 20%15 to 25% of the entire body’s energy both at rest and in action. Active, concentrated thinking varies this value by just one percentage point, so that normal passivity of the brain probably does not result in a significant energy gain. On the other hand, “switching off” the PFC due to massive stress could reduce energy consumption.16
The cooperation between the new and old parts of the brain is presented in a wonderfully understandable and entertaining way by Nobel Prize winner Daniel Kahneman in his highly readable book “Fast thinking, slow thinking”.17
4.3. Stress benefits of distractibility, task switching problems and attention problems¶
ADHD sufferers do not have an attention disorder per se. They can (in some situations) show very good attention and concentration. Anyone who has ever experienced an ADHD sufferer in hyperfocus, in which even highly monotonous activities can be carried out in a highly concentrated manner for hours on end, provided they are motivating enough to arouse the sufferer’s personal interests, and in which all irrelevant stimuli (in relation to the interest in question) are completely blocked out, can confirm this from their own experience. Against this background, it could be assumed that it is not the ability to pay attention and concentrate that is impaired in ADHD, but the control of attention. However, in our opinion, this conclusion also falls short.
According to our understanding, in ADHD there is neither a (technical) impairment of attention nor a (technical) impairment of attention control, but the control of attention is subject to a different mode (profile, leitmotif, program, pattern). This mode involves a stronger control by personal needs compared to the profile of attention control in a relaxed state. This control profile appears to be advantageous in survival-threatening situations: things of high personal interest are focused on even more strongly than usual (task switching becomes more difficult, even hyperfocus), attention is distracted more quickly from things that are of less interest to the person concerned. Attention is then less focused and more widely distributed. While the former allows for increased concentration on recognized dangers that need to be tackled, the latter causes a faster perception of and faster changes in attention to previously unrecognized dangers in less important activities.
If there are no such existence-threatening stressors, it is easier to focus attention on things that are not relevant to survival.
In the case of stress, attention must be focused primarily on the stressor that threatens the survival of the person. If there are no such existence-threatening stressors, it is understandable that it is easier to focus attention on things that are not relevant to survival. The term “relevant to survival” is the link to the concept of personal motivation: anyone who is exposed to a stressor that threatens their survival must decide for themselves what this is and how best to deal with it.
In ADHD, distractibility is not increased per se, but only the distractibility of tasks that are not considered important for problem solving out of personal interest. This can be seen, for example, in the fact that the attentional performance of ADHD sufferers in tests can correspond to that of non-affected people when the rewards are particularly high. More on this at ⇒ Motivational shift towards own needs explains regulation problems.
The advantage of increased distractibility is easy to understand if you imagine that the camp must always be guarded and approaching dangers should be recognized immediately, even during a nice conversation with another person around the campfire. From a stress perspective, it is therefore advantageous to be distracted by every noise, every movement or other “little things” around the campfire in the evening (or other activities that don’t really capture your interest). Those who were less “distractible” in times of danger were at a disadvantage - they discovered the attack or the approaching danger later.
Problems with spontaneously ending one activity in favor of another are not, at first glance, an appropriate reaction to a stressor. From the perspective of stress benefit, task switching problems are diametrically opposed to the symptom of distractibility.
What is the advantage of being difficult to disengage from a task once you have embarked on it?
According to our perception, the task switching problem occurs particularly when activities of special interest are performed. It is difficult for the person concerned to switch their attention away from things that are of particular personal interest to them - especially if the request to switch tasks relates to something that does not correspond to their personal interests.
The advantage of task switching problems is when a source of danger is being observed or pursued. At this moment, everything else is unimportant and it is an advantage not to be quickly distracted by this (personally motivated) activity. Those who allow themselves to be distracted by trivialities during the fight were exposed to an increased risk of losing the fight.
In the case of distractibility and task switching requirements, it is primarily the controllability of attention that is affected. Under stress, attention must be and remain focused primarily on the existentially threatening stressor. This is reflected in the phenomenon of hyperfocus - people affected by stress can become completely absorbed in tasks that they internally consider important. If the affected person allows themselves to be distracted from important (survival) tasks, they are at a disadvantage. With regard to less relevant tasks, however, it is advantageous if the affected person can be easily distracted. In terms of increased vigilance against possible dangers, on the other hand, distractibility from unimportant things (things that the person concerned considers unimportant) makes sense and promotes survival.
From this perspective, it becomes clear that attention control is involved in both distractibility and task switching requirements. In ADHD sufferers, it is not the ability to pay attention itself that is altered, but its controllability and tractability. The picture drawn here could explain this impairment of controllability in such a way that attention must be focused primarily on the existentially threatening stressor when under stress. If there are no such existence-threatening stressors, it is understandable that attention can be directed more easily to things that are not relevant to survival.
This is consistent with the fact that ADHD sufferers perform almost as well as non-affected people in attention tests when given the appropriate interest or rewards18 This confirms that it is not the ability to concentrate or inhibit that is impaired per se, but that the ability to pay attention and concentrate, as well as to direct attention, depends solely on an existing personal interest. If sufficient motivation is created through appropriate (high) rewards (for which higher rewards are required for ADHD sufferers), the attention ability of ADHD sufferers can correspond to that of non-affected persons. This phenomenon can distort the test accuracy of attention tests to such an extent that ADHD sufferers who are highly motivated and interested in the test do not show any attention problems.
This confirms that the problem with ADHD is not a limitation of attention per se, and that the control of attention also functions in principle, although the control of attention follows a different model, as would be helpful in a survival-threatening emergency condition.
4.4. Stress benefits of delay aversion (e.g. impatience) and procrastination¶
The stress benefit of delay aversion is that the person concerned postpones fighting the stressor less.
Stress is conveyed: “Make sure the problem is solved immediately. You should not let a danger remain. Take care of your problem. Be active, don’t let yourself go. If something stops you on your way to solving your problem, try to work around it.”
The stress benefit of “now is always” is the core of what stress wants to do to protect our survival: defeat the danger, now, immediately, don’t rest until the danger is gone. There is no time to wait, it’s about survival.
At first, the coexistence of delay aversion and procrastination seems contradictory. However, both are typical and frequently described symptoms of stress and ADHD.
Here, too, the meaning of the symptoms becomes clear when one considers the ability to be motivated by personal interest.
Things that are interesting enough to motivate trigger procrastination aversion and impatience, while things that cannot arouse the necessary personal interest are procrastinated.
Personally motivating means not only intrinsically interesting things, but all things that they pursue as their own interests. This can also include not wanting to be late for work, which would be an extrinsic incentive. Personally motivating means all things that are not intrinsically desired goals. This often includes tedious tasks such as tidying up, laundry, tax returns or similar - things that are not necessary for survival.
From the perspective of stress under the assumption of a survival-threatening situation, this division makes sense. If you are fighting for your survival, you would do well to concentrate on this and do everything that helps to combat the stressor as quickly as possible. Anything that gets in the way of this will trigger unwillingness and discomfort. Impatience, not being able to wait and doing things in a kind of inner rush are the logical consequences of this. However, things that do not contribute to combating the stressor can not only wait, they should. Gathering nuts for the winter is quite rightly a lower priority in the face of a survival-threatening danger.
Not only unpleasant things are affected by this. Pleasant things are also procrastinated by ADHD and stress sufferers: The inability to enjoy things, which sometimes extends to the inability to relax, arises from the same root.
This explains the frequently observed and studied phenomenon of devaluing distant rewards: Rewards that are further away are worth less to ADHD sufferers than to non-affected people. Rewards that can be expected immediately, on the other hand, are valued by ADHD sufferers in exactly the same way as by non-affected people. This differentiation makes sense in the context of an acute, existentially threatening stress situation: survival is now. Everything else can wait.
4.5. Stress benefits of dysphoria during inactivity¶
Dysphoria with inactivity is an original and functional symptom of stress and ADHD and should not be confused with depression, where this symptom has become extreme and dysfunctional. Treating dysphoria with inactivity with antidepressants is counterproductive. ⇒ Depression and dysphoria in ADHD
Dysphoria with inactivity means that the affected person’s mood worsens (only) when they are at rest. Examples include being in a bad mood after coming home or during the first few days of vacation (until recovery has reduced the stress level to such an extent that the stress symptom of dysphoria with inactivity also disappears). Many sufferers therefore prefer active vacations, although these do not always cover the increased need for relaxation.
Mood is one of the strongest control elements of the psyche. Every individual unconsciously and spontaneously tries to do what is necessary to maintain a good mood.
If a bad mood always occurs during periods of inactivity, the individual will try to remain active.
Staying active, not leaning back and not being distracted from fighting the stressor by pleasant pleasures and thus continuing the fight against the stressor is the stress benefit of dysphoria during inactivity.
Persistent rumination can result from the same mechanism. Increased rumination is functional as long as constructive solutions are sought. Brooding also becomes dysfunctional at a certain level, e.g. if you only think in circles and miss out on the necessary sleep.
The purpose of dysphoria during inactivity seems to be to encourage the person affected to become active, to actively defend themselves against the stressor (“fight”) or to keep energy ready to flee (“flight”).
If a person’s mood deteriorates whenever they become passive, this will encourage them (usually unconsciously, but very effectively) to become and remain active. Increased activity generally increases the likelihood of survival.
The purpose is not to burden the affected person with a bad mood during their fight. A bad mood during activity would tend to reduce the performance of the activities and would have no control effect in favor of the probability of survival (away from passivity, towards activity). Dysphoria is therefore only present during inactivity.
A stress benefit of listlessness would not be plausible if one assumed complete listlessness. However, this is usually not the case. Lack of drive could be explained as a stress benefit if stress does not cause a general lack of drive, but instead reduces the drive for things that are less suitable for combating the stressor and increases it for things that are suitable for combating the stressor (which depends on personal interests).
Lack of drive is useful in dangerous situations if it relates to things that are not necessary to combat the stressor. Giving in to the spontaneous thought of going for a swim while the camp is surrounded by enemies is not really conducive to survival.
With stress, as with ADHD, the drive is not completely lost. From the perspective of those not affected, however, there is a lack of drive to do things that make sense in everyday life. Especially for unpleasant, irrelevant things such as cleaning or tidying up, the drive is actually lacking. However, the drive is still there for things that are personally motivating enough.
If depression is seen as a reaction to even more severe, unmanageable stress, the all-encompassing listlessness that then sets in could be seen as a way of ending the battle, of surrendering to the enemy.19
There are a number of studies on learned helplessness or hopelessness, which even showed in animal experiments on dogs how they gave up trying to escape an electric shock (even when they had the chance again).20
From an evolutionary biology perspective, it could be argued in a very simplified way that if the opponent has won and the individual has been captured, it may have made sense to stop fighting in order to avoid being killed. The fact that listlessness is directly linked to depression and that in ADHD both symptoms come and go very quickly in parallel would fit in with this.
However, depression is far more often the result of inflammatory reactions than of an immune response, which is why this evolutionary-biological view may be questionable.
More sophisticated theories describe depression in evolutionary terms as a useful strategy for guiding behavior. According to the Social Navigation Hypothesis (SNH), depression evolved to fulfill two complementary social problem-solving functions. First, depression induces cognitive changes that focus and enhance capacities to accurately analyze and solve important social problems, suggesting a social rumination function. Second, the costs associated with the anhedonia and psychomotor disturbance of depression may persuade reluctant social partners to provide help or make concessions via two possible mechanisms, namely honest signaling and passive, unintentional fitness blackmail. Thus, depression may also have a social motivational function.21
The neurophysiological mechanisms that trigger depression (these are immunologically triggered inflammatory reactions), on the other hand, can be seen explicitly as the result of a functional stress management reaction.22
The stress benefit is: survival is now. Everything else, everything that comes later, is only relevant once the current challenge has been successfully mastered. Stress therefore promotes a focus on the here and now, on the immediate. This weakens interest in things that are not immediately important for solving the problem at hand. From the perspective of maximizing problem-solving skills for the (potentially survival-threatening) challenge that exists right now, it is logical and correct to reduce interest in things that will only provide an advantage later. In terms of evolutionary biology, it is the logical consequence of a very correctly functioning attention control system: attention is directed preferentially to things that are necessary for survival, while interest in irrelevant things is reduced. It follows from this that, from an evolutionary biology perspective, acute and massive stress causes neither attention nor distractibilitynor attention control Disorders. Rather, all of these systems function perfectly - they simply follow a different model under severe stress. They correctly and functionally follow the model that is correct and conducive to survival under severe stress: survive now and put everything else on the back burner.
The evolutionary-biological stress benefit is likely to be that the person affected develops increased activity to eliminate the stressor or that pleasant activities (enjoyment) distract from it.
Stress is conveyed:
“Make sure that the problem is solved immediately. A danger should not be allowed to persist.
Take care of your problem. Stay active, don’t get distracted.
If something is stopping you on your way to solving your problem, try to work around it.”
The stress benefit of the inability to enjoy lies in concentrating on the stressor. Severe stress “says”: survival is important now - you can enjoy and recover later. With a healthy (short-term) stress response, this is correct and helpful. However, if the stress response systems are permanently activated (as in ADHD-HI), this results in an inadequate ability to recover and can lead to a vicious circle.
Inability to enjoy and self-worth
It is conceivable that this stress benefit would also be mediated by reduced self-esteem. The intrusion (the inner (unconscious) guiding principle) would be “I am not allowed to enjoy”. From the point of view of a healthy stress system, this would be completely correct: enjoyment is only permitted again without danger once the acute threat has been overcome. Such a self-esteem reaction as a direct consequence of stress would then not be a cognitive conclusion. Self-esteem problems are a common symptom of stress overload. At the same time, the symptom of rejection sensitivity, which is often regarded as the cognitive consequence of a self-esteem problem, is, in our experience, a directly neurophysiologically mediated ADHD symptom (see Rejection Sensitivity).
An increased ability to perceive can be helpful in stressful situations. Being able to see, hear or smell better increases the probability of survival in terms of evolutionary biology.
However, it is detrimental in the case of a permanently increased stress reaction that is not based on any actual danger, as it additionally increases the stress.
4.11.1. Stress benefits of being internally driven¶
It is helpful to remain active and on the move until the stressor has been dealt with or has passed. Inner drive is at the heart of what causes stress: it drives you to expend energy to counter the stressor.
Resting and relaxing does not make sense in the face of acute imminent danger (not even for the ADHD-I subtype). Only when survival is assured, only when the acute danger has been eliminated and the individual is safe again, is it possible to relax without danger from an evolutionary biology perspective.
Constantly having to do something is another form of expression of being internally driven. It keeps the person concerned constantly active in order to drive them to do something about the (supposed) stressor. From this perspective, this is a promising stress management strategy.
Why do ADHD-I sufferers react differently if hyperactivity is supposed to be a survival advantage? ADHD-I sufferers, who like all other ADHD sufferers also suffer from chronic overactivation of the stress response systems, have different stress management patterns than the hyperactive-impulsive ADHD-HI type. ADHD-I sufferers are more likely to react to stress by fleeing or playing dead than by hyperactivity. Deer, which remain silent for a long time when danger approaches in order to avoid being discovered, use a similar strategy (which they do not actively choose any more than humans choose their stress phenotype). But deer are also extremely tense inside. Because if they are discovered, they have to flee quickly. This explains why ADHD-I sufferers are not internally relaxed even when they are “dreaming away”.
Why are there different stress response patterns?
It is helpful for the survival of a species if a group has members with as many different stress response phenotypes as possible. If everyone were to strike immediately, the group would be extremely weakened if waiting and keeping still would have been the better reaction in this case - and vice versa. A group is better able to compensate for the loss of individual members than the loss of a large proportion of its members. This explanatory model fits with the fact that the stress phenotype is not strictly passed on from parents to their children, but is subject to a high degree of variability. This high variability helps the group to survive.
4.11.2. The stress benefit of dealing with the stressor / circling thoughts / rumination¶
Stress “wants” us to deal with the stressor. It often makes sense to take care of the stressor and deal with it until we come up with a solution or the stressor is resolved in some other way. This can lead to an intense inner confrontation with the stressor, to the point where we “can’t think about anything else”.
Sometimes the constant “using thoughts of the stressor” turns into a permanent brooding or circling of thoughts (rumination), which is characterized by a recurring sequence of the same thoughts (in the absence of creative modifications of the thoughts). Such circling of thoughts is usually not constructive in terms of finding a solution. It is therefore at best an unfruitful consequence of the stress benefit “preoccupation with the stressor”.
If your partner complains that “he/she is never really there, never with me, always thinking somewhere else”, this may be the external view of a constant preoccupation with the stressor or a circle of thoughts.
4.11.3. The stress benefits of “Doing what you’re doing, mostly in a rush”¶
If stress had an interest of its own (which it does not have, it is - from an evolutionary biological point of view - merely the collection of survival strategies that were so successful that their bearers were able to reproduce considerably more frequently and therefore pass on their successful strategies more often), it would want us to be very focused on dealing with the existing problems. Evolutionary biology is not about enjoying solving problems, it is about surviving.
Only when the fight for survival has been won, only when the stressor has disappeared, is there room for relaxation, enjoyment and the resulting recovery. Until then, a loan is taken out - you live at the expense of pleasure and relaxation. Whether this loan can ever be repaid is irrelevant at the moment of the fight for survival. If the person concerned does not survive, they no longer need to recover.
4.11.4. Stress benefit of “Difficulty to pursue a leisure activity calmly”¶
Just as stress serves to encourage the person affected to actively deal with the stressor, it also serves to prevent them from relaxing and indulging in a pleasurable activity while there are potentially life-threatening dangers.
In our view and from an evolutionary biology perspective, mood swings are an expression of the shift in perception to the here and now, which is triggered by stress in order to focus attention on the stressor. If our perception is focused on the here and now, it stands to reason that our mood will also follow the here and now more closely.
A negative self-image (you’re not good enough, do more to survive, don’t be satisfied with what you’ve done so far, stay active to get better) could also be a motivation to change previous habits and master the acute challenge. However, the concepts of self-esteem understand this as a consequence of cognitive processes. It is therefore rather unlikely that negative self-esteem is a direct consequence of stress.
Aggressiveness increases the willingness to fight, just as fearfulness increases the willingness to flee.
Fighting was much more important and beneficial at the time when our stress systems were created than it is today.
At first glance, the two stress benefits of aggressiveness and anxiety seem contradictory. If aggressiveness is a stress benefit, how can anxiety be equally useful?
Stress symptoms are not a uniform reaction to every stressor, but vary depending on which stressor occurs. It is obvious that neither an aggressive nor an anxious reaction is appropriate for the stressor hunger. In contrast, an aggressive reaction (fight) or an anxious reaction (flight) is more appropriate for some other stressors.
However, it is clear that people differ according to the extent to which aggressive or anxious forms of behavior predominate.
The apparent contradiction is resolved if one considers not only the stress benefit for the individual, but also the stress benefit for the whole group or species. See below under 13 Individual variance of stress symptoms as a survival advantage for the group and species.
4.13. Frustration intolerance as a stress benefit consequence¶
Frustration intolerance could be a consequence of the massively increased striving to eliminate the stressor. An existentially threatening stressor must be eliminated as quickly as possible. If individual solution approaches do not lead to the desired result, it would be advantageous to expend more energy to try other solution strategies.
It should be noted that a simultaneous parameter is extreme time pressure, which is why the “clever” solutions of slow thinking are not helpful.
A stress benefit of rejection sensitivity is not clearly recognizable. It could lie in not using one’s resources in difficult times on people where it is not certain that the investment will be reciprocated. However, this does not explain why rejection is so aversive and not just a selector of who to turn to.
The increased risk of being expelled from the group as a result of rejection is a particularly intense stressor in its own right.
Tend and Befriend has the stress benefit of increasing the bond with the group in dangerous situations.
Similar to aggression and anxiety, which are developed preferentially depending on the stressor, and which have different stress benefits (fight versus flight), rejection sensitivity and Tend and Befriend can also make sense in an individual at the same time. The translation could be: Attach more strongly to those who reciprocate the affection and accept the attachment, and stay away from those group members where you can’t be sure of the return on your investment in an attachment.
This dualism is particularly pronounced in borderline patients (whereby borderline patients are often unable to accept an attachment because they do not feel worthy of it and because the fear of losing an attachment is significantly greater than the benefits of the attachment itself).
In the times in which the stress benefits of our stress systems emerged, exclusion from a group was almost tantamount to a death sentence. Men still had a slightly greater chance of surviving for a while as lone fighters and hunters, which could explain why Tend and Befriend is more pronounced in women than in men.
The purpose of anxiety as a stress symptom is to try to escape.23
The feeling of constantly having to do something (above under hyperactivity / restlessness / being internally driven) goes hand in hand with the subjective impression of those affected that they get far too little done, don’t get anything done, are underperformers and inadequate.
This perception is the way in which stress ensures that the person concerned remains active. The feeling of having achieved enough would pave the way for a certain satisfaction and thus a permitted relaxation. However, this would be dangerous in the case of an acute threat, which is the underlying stressor of the stress response, as it would weaken the drive to fight the threat.
Stress tells the person experiencing it that their previous problem-solving strategies are inadequate. Stress communicates immediately: “You are not okay the way you are (so far) - because you are in an extremely dangerous situation. Move, change so that you can survive. What’s more, your previous stress management strategies have put you in this situation. That’s why you shouldn’t feel good about the way you are.”
It goes without saying that this is directly detrimental to self-esteem. A high self-esteem would mean that you are satisfied with yourself as you are. Then there would be no reason to change anything about yourself. But stress alarms us precisely because something needs to be changed.
This is why severe stress also loosens the neuronal circuits in the brain in order to be able to dissolve the previous, dysfunctional problem-solving patterns that are mapped in the neuronal circuits and to be able to replace them more easily with new circuits. Conversely, stress strengthens and reinforces neuronal circuits when stress is successfully managed in order to anchor the last successful coping strategy more deeply in the brain and promote its automation.
Increased anxiety causes increased caution. If life-threatening circumstances (presence of predators) increase caution, this increases the probability of survival.
If the anxiety becomes so great that it no longer merely increases caution but inappropriately impairs the ability to act, the functional stress symptom of anxiety has become dysfunctional and crosses the threshold into an anxiety disorder.
4.18. Stress benefits of inner emptiness and alexithymia¶
Inner emptiness is the logical consequence of focusing on the stressor (see above under circles of thought). It is conducive to survival if fighting the stressor is the only thing that really counts. Nothing should distract from this, not even the perception of your inner state, other desires or (even good) feelings. Feeling good could tempt you to just get on with it and have a good time - instead of dealing with the threat.
4.19. Stress benefits of reduced / increased empathy¶
The stress benefit of reduced empathy could lie in greater selfishness in problem solving, which increases the probability of survival. In the physical struggle for survival with an enemy, empathy for their suffering is a hindrance.
Within a group, increased compassion for others is a bonding tool that counteracts exclusion from the group, which would be even more detrimental in dangerous times.
These opposing stress benefits could make it plausible that people who externalize their stress (ADHD-HI: fight) benefit from decreased empathy, whereas for people who tend to internalize their stress (ADHD-I: flight, play dead), increased empathy is beneficial (Tend and be friend).
A stress benefit of novelty seeking could conceivably be the search for new ways and means of coping with challenges. From the perspective of the individual, however, this appears to be rather disadvantageous, as the resources required for this are likely to be too high and resources tend to be conserved during extreme stress. It is possible that the stress benefit lies in an advantage for the species.
The preference for high-risk sports has already been described as a possible consequence of stress.
4.21. Stress benefits of increased willingness to take risks¶
A stress benefit from the affinity for risk and risky sports could result from the fact that their stimulus intensity is so great that those affected can (have to) finally fully engage with something. A kind of hyperfocus could be induced.
It is also conceivable that risk-taking, which is a stressor in its own right, is better able to mask the latent undefined stressor that exists in ADHD than other activities that offer no stressful stimuli and can therefore more easily fall into the category of “pleasures not allowed now”.
4.22.1. Stress benefits of “Small talk is perceived as boring”¶
The purpose of stress is to focus the person’s interest on issues that will help them to solve their problem. All other things are unimportant. Stress is therefore more successful when things that do not arouse the person’s interest seem unimportant and irrelevant.
This phenomenon becomes more understandable if one considers that the deviation in attention control during stress is primarily due to the factor of motivational capacity (which is reduced in ADHD). Things that the affected person personally considers interesting (in the case of stress, things that can solve their problem) attract attention. With a high level of personal motivation, ADHD sufferers are also very good at blocking out all other things (low distractibility). On the other hand, what others want, what the affected person should be interested in without actually doing it, is considered unimportant. Those affected are very easily distracted from these things.
Even if someone has fully understood cognitively that it is good for them to be interested in something now (e.g. the binomial formulae or the grammar of the infinitive in order to get good grades and not get into trouble at home) and they also have the will to achieve good grades and not annoy anyone at home, this does not arouse any personal interest. Apart from that, good grades are not important here and now and at home is also very far away in the classroom - and therefore uninteresting.
4.22.2. Stress benefits of “conversation partners hardly get a chance to speak”¶
The same explanation applies here as for the fact that small talk is perceived as boring. The hyperfocus of those affected on topics that interest them causes a shift from personally less interesting to personally more interesting topics that are more suitable for motivating the person concerned.
As the acute problem of the person affected is greater than the needs of others who are not under severe stress, this is even socially legitimate to a certain extent. It would be interesting to observe whether people affected by stress select according to this.
With the symptoms
Speech diarrhea, talkativeness, word overload (Logorrheapolyphrasia)
Speaking quickly and indistinctly
Impulsive disregard for social rules
Interferes in conversations / activities of others without being asked
no stress benefit has yet been defined.
4.23. Organizational difficulties as a consequence of stress¶
Problems of organizing tasks and activities have no stress benefit of their own, because organizational skills are advantageous when solving serious problems. However, if you look at the examples given, they can be recognized as a consequence of other stress benefits.
Stress shifts the person’s focus to the stressor, e.g. to ensure acute survival. People who are in the process of putting out a fire in their bedroom have a very healthy reduced interest in a tidy living room compared to others who are not in the middle of a fire.
The main purpose of stress is to shift priorities: “Take care of the stressor now - everything else is unimportant at the moment and can wait.”
When such stress is a permanent condition (as in ADHD due to the shift in thresholds at which the stress systems kick in for uncontrollable stress), and as a result the priority shift is a permanent condition, this inevitably leads to many things not being able to be handled with the same level of priority and calm that the people around you apply, either today or tomorrow, or for that matter anytime soon.
4.23.1. Not (being able to) keep promises or commitments to others as a stress benefit consequence¶
Here, too, there is no immediate stress benefit, but the impaired ability to keep promises or commitments to others is the result of the stress benefit of focusing on the stressor that is currently being combated. This is (also) achieved by making things that are not immediately useful for one’s own survival seem less important. It is plausible that everyday things become relatively less important when the focus is shifted to the fight for survival.
If an appointment is made, the focus of perception (at the moment of the appointment) is on this meeting. If the person concerned then has to set off while they are busy with something else, the other thing is always more important because it is “here and now”. All things that are further away are less important from the point of view of the stress response. Stress is always a focus on the problem to be solved here and now and puts all other problems that are not immediately relevant at the moment on the back burner.
This explanation seems more direct and comprehensible to us than the sources of time estimation errors and structuring deficits mentioned in the specialist literature to date.
4.23.2. Problems doing things in the right order as a stress benefit sequence¶
This symptom is also a consequence of the stress benefit of valuing the here and now more highly and taking everything else less seriously. Stress changes priorities. Things that are considered personally important are prioritized higher. From the point of view of stress, this is highly expedient.
If a person is (understandably for others) under acute severe stress, e.g. because a loved one is in hospital undergoing a serious operation, nobody would expect them to assemble an Ikea cabinet in the right order straight away. However, if the person concerned can do something to help save their loved one, they will be able to concentrate on this much better, as this will arouse their personal interest enough to motivate them.
In addition, a strongly increased noradrenaline level (as is often the case with ADHD-I) impairs the PFC and thus the working memory. The stress benefit here lies in the shift of behavior control from slow, precise brain areas (PFC) to fast, imprecise planning brain regions, as this is more advantageous during fight or flight.
Not the excessive demands themselves, but the feeling of excessive demands could be helpful from the point of view of stress in order to activate the person concerned to make even more and greater efforts.
This is countered by the fact that a particular enjoyment of an activity would be even more effective.
The feeling of being overwhelmed could be intended to make you think about how you can solve the problem differently or to motivate you to seek support and help.
4.26. Time estimation error as a stress benefit sequence¶
Time estimation errors have no direct stress benefit. However, they could be related to the fact that stress causes waiting and inactivity to be perceived as unpleasant in order to encourage the person concerned to become active immediately.
Stress also wants the stressor to be dealt with immediately. Stress causes a different experience of time: now is important, everything else doesn’t count. People affected by stress have an altered perception to the effect that only what is happening right now is true and valid, forever. This is reminiscent of a kind of black and white temporal thinking.
The stress benefit of sleep problems could lie in the promotion of rumination (or be its consequence), the stress benefit of which is the intensive confrontation with the stressor and the search for ways out and solutions. As stress is not designed as a long-term solution strategy, the aspect that reduced recovery impairs the ability to find solutions is less relevant. Poorer sleep could also make it easier to wake up when danger approaches.
5. Stress symptoms that are not typical ADHD symptoms¶
There are a number of stress symptoms that are not referred to as ADHD symptoms in the ADHD literature. These are primarily physical stress symptoms.
In many cases, the differentiation within the explanatory model advocated on this side could be explained by the fact that these are secondary stress symptoms that are not directly mediated via the HPA axis - e.g. psychosomatic complaints such as abdominal pain or back pain.
Somatic complaints (with the exception of sleep problems) could be another type of stress that occurs significantly less in ADHD sufferers than in non-affected people (under stress).24 This circumstance could be explained according to the model described in the introduction under 13.
However, the studies on this side (at low n) also indicate - earlier to our own astonishment - that somatic stress symptoms are clearly underrepresented in adults with ADHD. The only exceptions are sleep disorders (very clear) and states of exhaustion and muscle tension (still clear). In contrast, all other somatic stress symptoms are rarer than in non-affected persons.
Sexual problems with reduced libido are a symptom of stress.252627
Suppression of the libido is a direct effect of the stress hormone CRH.2829
Sexual problems or listlessness are not specific ADHD symptoms, but nevertheless occur frequently. Disordered sexuality is mentioned as a frequent comorbidity in ADHD.30 Sexuality is also mentioned as an addiction and a means of relieving tension in ADHD31
The number of sexual partners with ADHD is typically increased, and the first sexual intercourse takes place earlier on average than in those not affected. A decrease in libido is mentioned in connection with medication for ADHD.32
Increased muscle tension is mentioned as a stress symptom.2633
The stress benefit of increased muscle tension is a reduced risk of injury in combat.
Increased muscle tone (which usually occurs at night) can, for example, lead to considerable back pain and even vertebral blockages in the medium term. Seen in this light, back pain is often a consequence of stress.
With this in mind, it is right not to see these as direct ADHD symptoms. This does not change the fact that they are common stress symptoms that can also occur with ADHD.
Eating problems are not direct ADHD symptoms, but often occur comorbidly.
Obesity is at least twice as common in people with ADHD as in those without the disorder.
Eating disorders are up to 8 times more common in people with ADHD than in people without the disorder
More on this in the article ⇒ ADHD, obesity and eating disorders.
There is a strong correlation between obesity and ADHD, at least in adults.34
ADHD sufferers with obesity are more likely to show high impulsivity than ADHD sufferers of normal weight. Impulsivity could be the connecting element between obesity and ADHD.35
Some people react to stress by changing their weight. Weight loss or weight gain is possible.
Loss of appetite is a symptom of stress.26272829
Loss of appetite is a direct effect of the stress hormone CRH.2829
Weight gain as a stress reaction could be interpreted in evolutionary terms as increased storage of energy in emergency situations. As the stress systems are activated more frequently in ADHD (ADHD-I) or do not switch off properly and are therefore permanently activated (ADHD-HI), the above-average incidence of obesity in ADHD could be understood as a stress symptom of those affected.
Frequent colds / infections are a symptom of stress.25 An increased susceptibility to infections is a typical symptom of the approaching final state of burnout.37
Stress hormones (adrenaline, CRH, cortisol) are able to artificially boost the immune system for a certain period of time. For the species of Homo sapiens, it was simply conducive to survival if, in situations of need in which survival had to be fought for, not exactly simple (avoidable) diseases were added. The stress hormones adrenaline and CRH therefore cause a (temporary) inflammation-promoting increase in the activity of the immune system.
However, on the one hand, this increase is exhausting and, on the other hand, during the first stress break it leads to the body taking the necessary time to regenerate and actively combat illness - e.g. through fever and other mechanisms with which the body protects itself against pathogens.
This is the reason why people who are stressed at work often fall ill during the first week of their vacation.
In addition to its effects in mediating stress symptoms, cortisol also has the task of ending the stress reaction (by inhibiting the hormones released at the beginning of the stress chain and thus limiting its own release over time). Cortisol also reduces the pro-inflammatory effect of adrenaline and CRH and instead promotes other immune reactions, which are primarily directed against bacteria and parasites. Depending on the direction in which the stress systems are out of balance, excessive inflammation (e.g. of the intestinal mucosa in Crohn’s disease or of the skin in neurodermatitis) or excessive immune reactions against external pathogens (e.g. allergies) can occur.
Increasing respiratory rate is a symptom of stress.2638
6. Individual variance of stress symptoms as a survival advantage for group and genus¶
The parallel occurrence of aggression and anxiety in similar situations in different individuals is sometimes advantageous for some and sometimes for others. The parallel distribution among individuals is a survival advantage for the species. If the members of a group have different stress reactions, this ensures the survival of the group better than if all individuals had the same reaction.
If a particular stress response (e.g. impulsive-aggressive) is less suitable for successfully combating the stressor, only those individuals that carry this stress response phenotype are at a disadvantage or at risk of extinction. If, on the other hand, the wait-and-flee or kill variant is less suitable, these individuals do not survive as well - while the more aggressive individuals have advantages.
In a group, there is also the fact that, depending on their personal aptitude, some individuals take responsibility for solving different problems, while others do so for the benefit of the group as a whole.
Different stress response patterns increase the probability that at least some individuals in the group will survive.
7. Stress benefits explain the difference between ADHD and other mental disorders¶
Many symptoms of ADHD are functional stress symptoms. Functional means that they have a benefit for the individual in the struggle with a stressor - assuming that there is an acute and massive threat to the existence of the person concerned.
The symptoms of most other mental disorders (anxiety, depression, compulsion) can be distinguished from the fact that they are usually no longer functional but dysfunctional stress symptoms. Dysfunctional means that there is no immediate stress benefit from the core symptom(s).
The degree of listlessness and hopelessness that characterizes depression is not suitable for combating the stressor.
One could perhaps still see a stress benefit in the fact that the active fight against the stressor is now lost, and it is then more conducive to survival to accept this than to continue fighting the stressor, as this could involve further energy losses and, above all, the risk of being killed. This would be a recognizably different state of fighting a stressor. However, this idea possibly overstretches the picture of stress benefit.
