Dear reader of ADxS.org, please excuse the disruption.
ADxS.org needs around €58,500 in 2024. Unfortunately 99,8 % of our readers do not donate.
If everyone reading this appeal made a small contribution, our fundraising campaign for 2024 would be over after a few days. This appeal is displayed 23,000 times a week, but only 75 people donate.
If you find ADxS.org useful, please take a minute to support ADxS.org with your donation. Thank you very much!
Since 01.06.2021 ADxS.org is supported by the non-profit ADxS e.V. Donations to ADxS e.V. are tax-deductible in Germany (up to €300, the remittance slip is sufficient as a donation receipt).
Motivation in relation to ADHD can be divided into1
Internal motives
Determine the direction of behavior
Focus on a result or goal
Energy
Determines the intensity or strength of the commitment
Endurance
Time commitment of the engagement
The internal motives (needs, cognitions, emotions) serve as mediators between external triggers on the one hand and the behavior / performance on the other.2
The motivation of people with ADHD differs from that of people without ADHD. Motivation is not impaired per se, but is subject to a different mode of regulation. The ability to motivate in people with ADHD is lower overall and more strongly oriented towards satisfying their own needs than in people without the disorder. Studies show that motivational capacity in ADHD can be influenced by intrinsic and extrinsic incentives.
Intrinsic motivatability also appears to be weakened. A reduced neurophysiological response to anticipated rewards and an increased response to received rewards explain the shift in motivatability towards immediately available rewards. Rewards may influence reaction times and response variability in ADHD. Inhibition problems and working memory problems in ADHD can be improved by rewards, but people with ADHD often do not reach the level of non-affected people. The motivational problems in ADHD also have an impact on frustration intolerance, impatience, procrastination and emotional dysregulation.
On average, people with ADHD require significantly higher extrinsic (external stimuli, e.g. rewards, Compulsions, threats of punishment) or intrinsic (self/self-induced) incentives than non-affected people to achieve the same level of personal motivation. We believe that this leads to motivation in ADHD being (somewhat) more strongly directed towards satisfying one’s own needs and less strongly guided by the needs of others than in non-affected individuals. What may look from the outside like a slightly increased selfishness is, however, an unconscious shift in what can arouse individual motivation and is not subject to conscious control by the person with ADHD.
Motivation controls attention. Attention functions differently in people with ADHD than in those without, but is not impaired overall. Attention in ADHD is more dependent on high individual motivation. Attention can also be very focused and long-lasting in ADHD - with the right motivation.
The problem is that people with ADHD are much less able to control their motivation than people without ADHD.
There are numerous studies that demonstrate the motivational deficits in ADHD. Children and adolescents with ADHD often show difficulties in maintaining motivation and work behavior. These problems can also affect academic performance and long-term functioning. The motivational deficits in ADHD affect both extrinsic motivation (external incentives) and intrinsic motivation (own interest and enjoyment in an activity). Some studies suggest that the motivational deficits in ADHD are related to reduced activation of the reward system in the brain.
The studies also show that other factors such as frustration tolerance, impulsivity and emotional instability can influence motivation in ADHD. Individual differences in stress management and the processing of reward signals may also play a role.
Neurological studies have shown that in ADHD patients, dopamine levels in the brain are reduced and activation in the nucleus accumbens, a region involved in the processing of rewards, is reduced when a reward is expected. In contrast, activation is increased when a reward is received. These changes in motivation in ADHD are similar to those in chronic stress. The stress hypothesis states that the symptoms of ADHD and chronic stress are mediated by similar neurophysiological mechanisms. In particular, a lack of dopamine and noradrenaline in certain regions of the brain such as the dlPFC, striatum and cerebellum plays a role.
Knowledge of the neurophysiological basis of motivation in ADHD can help to develop better diagnostic and therapeutic approaches. Interventions to improve motivation in ADHD could, for example, aim to increase the activation of the reward system in the brain or teach stress management strategies.
The relationship between inattention and (poor) academic performance is explained by the degree of concurrent intrinsic motivation and behavioral engagement, but not by the degree of concurrent hyperactivity/impulsivity, conduct problems, or anxiety.6
Motivation or motivatability (like attention) is not inherently impaired in ADHD, but is subject to a different regulation mode / control profile. When motivation is particularly high, people with ADHD (also in attention tests) can barely be distinguished from people without ADHD. The difference lies rather in the lower level of self-motivation, which can easily be mistaken for unwillingness or laziness from the outside.
We assume that the ability to be motivated is more strongly oriented towards satisfying one’s own needs than in the case of those not affected.
For us, this would be a logical consequence of the fact that the symptoms of ADHD are mediated by the same neurophysiological pathway as the symptoms of chronic stress (primarily reduced dopamine and noradrenaline levels in the dlPFC, striatum and cerebellum). One stress benefit is an increased assurance of one’s own survival. In this context, a tendency to prioritize selfish behaviors would be expected. So far, we have found very few studies dealing with ADHD and selfishness. One study of 90 adults with ADHD found significantly increased egocentrism.7 Another study found a weak correlation between egotism/narcissism (as well as callous unemotional traits) and ADHD.8
Not meant, but possibly correlating, is that people with ADHD are apparently less able to take the (visual) perspective of a conversation partner.9
Intrinsic needs can be addressed by intrinsic motivation / interests, where the thing itself arouses the interest / motivation of the individual, as well as by extrinsic motivation / extrinsic interest (Compulsions, threat of punishment, rewards).
Hypothesis of a shift in motivational capacity towards intrinsic needs questionable / not yet proven
We had previously assumed that intrinsic motivational capacity was less impaired and that motivational capacity would be shifted towards intrinsic motivation. Studies have so far not confirmed this, although there are probably only studies relating to academic intrinsic motivation in ADHD.
What is evident, however, is a reduced neurophysiological response to anticipated (expected) rewards and an increased neurophysiological response to received rewards, which may explain the shift in motivational capacity towards immediately available rewards and the associated devaluation of distant rewards (reward discounting).
We have not yet found any studies to support our hypothesis that this is accompanied by a shift in motivational capacity towards the satisfaction of personal needs.
1.1. Motivability through extrinsic / intrinsic incentives¶
1.1.1. Extrinsic motivational ability weakened in ADHD¶
As many studies have shown, extrinsic motivation is weaker in people with ADHD than in those without the disorder. Extrinsic incentives must therefore generally be significantly higher for people with ADHD than for those without the disorder in order to arouse the same level of motivation.10
This article contains many references to sources that show that in ADHD, increased extrinsic incentives are able to reduce various symptoms through the motivation achieved in such a way that they no longer appear much more clearly than in non-affected people or even reach the level of non-affected people, e.g. (sustained) attention, inhibition (impulsivity suppression), parts of working memory and probably also frustration intolerance. The effect of motivation created by increased incentives has not yet been investigated for most other ADHD symptoms.
1.1.2. Intrinsic motivational ability also weakened in ADHD¶
A study on (academic) intrinsic motivational ability in ADHD found that this also appears to be weakened, affecting ADHD-C and ADHD-I equally.11 Another study found that in adolescents with ADHD, the academic intrinsic motivational ability with d = 0.49 was even more attenuated than the academic extrinsic motivational ability with d = 0.43 (in each case in comparison to non-affected persons).12
Another study hypothesizes that a slower event rate on tests in people with ADHD causes reduced intrinsic motivation due to their specific motivational characteristics.13 The authors also point out that, under certain circumstances, an external incentive can undermine an individual’s intrinsic motivation. However, this generally well-studied effect has not yet been tested in people with ADHD.
One report discusses the importance of intrinsic (internal) motives in ADHD and their assessment using Self Determination Theory (SDT).2
1.2. Reward sensitivity according to behavior / activity of the autonomic nervous system¶
Reward sensitivity can be divided into external reward sensitivity, defined as behavioral approach motivation in response to reward (i.e., reward-seeking behavior)14, and internal reward sensitivity, defined as the threshold of the nervous system for responding to reward, indexed by sympathetic nervous system activity, nucleus accumbens, or dopaminergic fronto-striatal brain regions)15.
In terms of behavioral reward sensitivity in children with ADHD, results suggest increased reward sensitivity in ADHD, with high rewards having a very large effect and immediate rewards being significantly preferred.16 Some studies concluded increased behavioral reward sensitivity in children with ADHD due to
A preference for small immediate rewards compared to larger delayed rewards17
Devaluation of delayed rewards / delayed discounting18192021
A small study found no difference in ADHD, but a decrease with age22
Using the Balloon Analogue Risk Task (BART), one study found a 27% reduction in behavioral reward sensitivity in ADHD (5.0 pops) compared to non-affected individuals (6.35 pops), which in our opinion is not consistent with the authors’ assessment that there were no differences. The reduced behavioral reward sensitivity in ADHD was also evident in the measurement of PEP (prolonged in ADHD) and RSA (HRV decreased)24
1.2.2. Reaction threshold of the autonomic nervous system¶
With regard to neurophysiological reward sensitivity in children with ADHD, the results indicate an altered response threshold of the autonomic nervous system in ADHD.25 PEP was found to be prolonged and RSA (HRV) decreased in ADHD.24
PEP and RSA: what they mean
The PEP represents the mesolimbic dopamine reactivity, particularly during the reward response.26 A longer PEP is a marker for reduced activity of the sympathetic nervous system, even if this can also be influenced by other factors.27
Respiratory sinus arrhythmia (RSA) consists of oscillatory increases and decreases in heart rate during the respiratory cycle. It represents parasympathetic / vagal effects on the heart. The RSA is thought to represent neuronal traffic through the vagus nerve28. The vagus nerve is thought to represent a physiological mechanism for the rapid acceleration and deceleration of cardiac output (heart rate variability, HRV) in response to environmental (including social) demands.29
ADHD subtypes appear to differ in terms of the incentives that can increase their motivation. One hypothesis is that different incentives may help different ADHD subtypes to improve their motivation. ADHD-C, which (like the predominantly hyperactive ADHD-HI subtype) carries more competitive traits, should be better encouraged through the use of game-like learning approaches and public recognition of their performance, whereas the predominantly inattentive ADHD-I subtype, which carries more cooperative traits and is more often distracted by their own intrinsic curiosity, is more likely to be motivated by cooperative forms of learning and social feedback. This applies in particular to teaching interventions and the style of didactic support during learning.11
In studies on reward behavior, different incentives are used depending on the type (e.g. money, gifts, points, computer games) and intensity of the reinforcement (e.g. 5 ct, 25 ct, 1 point, 100 points).30
The fact that some studies found no change in the symptoms of ADHD due to rewards could possibly be due to the fact that the respective rewards were not able to arouse the individual’s interest sufficiently.30. However, the authors’ study on working memory in ADHD found a significant improvement even with very high rewards, but no complete equalization of working memory performance compared to non-affected individuals.
Monetary rewards generally provide the strongest motivational incentive.
One study found that although social rewards improved impulsivity relatively more than in people not affected, monetary rewards were the strongest motivator in both people with ADHD and those not affected.31
Monetary incentives seem to work better as rewards (for women) than punishments to be avoided through verbal feedback.32
2. Attention in ADHD: not impaired, but different¶
Attention in people with ADHD differs significantly from that of people who are not affected. Nevertheless, the ability to pay attention is not impaired in ADHD per se. The ability to direct attention itself is also unchanged - attention in ADHD can be very focused (keyword: task switching problems, hyperfocus) or easily switched (keyword: distractibility).
Attention differs in ADHD from non-affected individuals in that its control is subject to a different control profile. ADHD correlates with a reduced neurophysiological response to anticipated (expected) rewards and an increased neurophysiological response to received rewards, which explains the shift in motivational capacity towards immediately available rewards and the associated devaluation of distant rewards (reward discounting).
We hypothesize that attention control in ADHD is more dependent on a high level of individual motivation. If something is personally very interesting, attention can easily remain focused on it; if it is not very interesting, attention switches more easily than in non-affected individuals. In people with ADHD, attention control is much more dependent on satisfying one’s own needs than in those who are not affected. However, this is not selfishness, but an altered control of motivation over which the person with ADHD has no influence.
What looks from the outside like “You can do it if you want to” is actually “I can’t want to do what I’m supposed to”.
Non-affected people are subject to the same deviating attention control profile when they are under severe acute or chronic stress. For such emergencies (e.g. in life-threatening situations), such an attention pattern is helpful and has been useful for survival over the past centuries.
The problem with ADHD is that this attention control profile is permanently activated, even though there is no corresponding life-threatening situation.
Even if it initially seems logical that a weakening of motivability is accompanied by a relative focus on things that are of personal interest, we have not yet been able to find any scientific evidence for the hypothesis that motivability is shifting towards personal interests.
Brown describes the interest-driven change in attention for ADHD as a tendency to focus attention excessively on things that interest.33 Anxiety and depression are subject to a similar perceptual bias towards distressing/frightening topics.3435
In ADHD, deactivation of the default mode network (DMN), which is deactivated when attention to external stimuli is activated, is reduced. Interesting rewards such as stimulants are able to equalize the deactivation of the DMN in persons with ADHD to that of non-affected people.36
The focusable attention of persons with ADHD is also demonstrated by the fact that they can achieve the same performance on ADHD tests as people without ADHD if they have a high level of personal interest in the test. This often leads to false negative test results. (Extrinsic) rewards that are high enough to arouse personal interest produce the same result.3738394041
One study found that frequent reinforcement leveled the differences in sustained attention between people with ADHD and those without, while infrequent reinforcement allowed the differences to persist. This particularly affected the younger children.42
More on this at ⇒ People with ADHD perform as well as people without ADHD in tests if interested
The fact that an insufficiently stimulating environment (underactivation) can also cause inattention in healthy people, e.g. in gifted children in schools not suited to their abilities,43 is probably not due to an altered control profile of attention, but rather to an underchallenge that causes boredom.
2.1. Task switching problems and distractibility in ADHD¶
If something particularly interesting to the individual (high individual motivation) is done, task switching problems arise. Attention is strongly absorbed and it is difficult to switch attention to other things. In extreme cases, this condition is called hyperfocus, and the resulting symptom is task switching problems.
If the current activity is not particularly interesting for the individual, distractibility is increased. Attention is then less focused and is easily directed towards new stimuli.
3. Inhibition problems disappear with high individual motivation¶
Impulsivity in ADHD (inhibition ability) can also be influenced by rewards.44 In children with ADHD, rewards led to results in the stop task that corresponded to those of the controls, while the same rewards improved inhibition to a lesser extent in children with brain injuries.45 The reward for a successful stop task here consisted of immediate positive feedback on the screen (e.g. “Well done” / “Great” / “Keep it up”) and a point added to the score, with the children being able to convert the points into sweets or small toys after the test.
Another study also found an identical inhibition ability of persons with ADHD and non-affected people with high rewards.46
Another study found a greater improvement in inhibition and sustained attention in people with ADHD than in those without,31 another study found no improvement in inhibition ability as a result of rewards.47 The reward here was 25 dollar cents for a successful inhibition in a modified stop-task test with a loss of 10 dollar cents for an incorrect test run. It is conceivable that the form of the reward in this test was unable to arouse sufficient individual motivation.
Various studies show that rewards improve inhibition skills not only in ADHD, but also in substance abuse or gambling addiction.48
One review summarizes that in ADHD, impulsivity correlates with decreased striatal activity during reward anticipation, while in healthy individuals, impulsivity is associated with increased striatal activity during reward anticipation.49
4. Reward improves working memory and long-term performance in ADHD¶
ADHD is associated with impaired working memory.
In one study, children with ADHD showed significant improvements in working memory for rewards, but did not reach the level of non-affected children even for the strongest rewards (€10 and gaming). Only children with ADHD showed a decline in performance over the duration of the test. However, high rewards were able to eliminate this decline in performance.30
One study found that in children with ADHD-C, rewards (feedback after each trial and points redeemable for prizes) improved visuospatial working memory for the manipulation of stored visuospatial information (backward span). In contrast, there was no improvement in the storage of visuospatial information (forward span). There was no comparison with non-affected individuals.50
Another small study also found improvements in visual-spatial working memory through extrinsic rewards.51
One study found that the frustration still detectable in ADHD subjects with low rewards in the first test runs no longer occurred with higher rewards.41 Another study found no improvement in frustration tolerance in ADHD through rewards.52
6. Impatience and procrastination in ADHD: motivation makes a difference¶
Things with high personal motivation have to happen immediately for people with ADHD. Impatience and not being able to wait are typical consequences of this.
Things for which there is low personal motivation, on the other hand, are procrastinated more often than by those who are not affected, such as opening unpleasant mail (unlike the longed-for call from a loved one), doing the tax return or taking out the garbage.
This pattern exists in all people to a certain extent. In ADHD, however, it is drastically increased and leads to dysfunctional results.
7. Emotional dysregulation and reward expectation¶
In a study on healthy individuals, emotional instability correlated with reduced activation of the striatum during reward anticipation only in women, but not in men.53
In a go/nogo task, children with ADHD responded more slowly and variably than their unaffected siblings or controls. A slower event rate did not reduce the performance of the people with ADHD. Under reward, only the persons with ADHD and their unaffected siblings showed accelerated mean response times and lower response variability, but not the controls, while accuracy improved in all 3 groups. Males responded faster and showed more false alarms, regardless of ADHD status.54
Until 2013, no published study had examined the impact of rewards on delay discounting in ADHD.55
It is known that children with ADHD do not show symptoms of attention problems, distractibility or hyperactivity when they are engaged in an intrinsically highly motivating activity (e.g. computer games).
The changes in motivation in ADHD, including the underlying neurophysiological correlates (decreased dopamine levels / decreased activation in the nucleus accumbens when reward is anticipated and increased activation of the nucleus accumbens when reward is received) correspond to those in chronic stress. ⇒ Neurophysiological correlates of reward in ADHD
This is consistent with our hypothesis that the symptoms of ADHD and the symptoms of chronic stress are mediated by very similar neurophysiological mechanisms (primarily dopamine and noradrenaline deficiency in dlPFC, striatum and cerebellum).
Barkley (2015). ADHD as a Motivation Deficit Disorder. In Barkley (Herausgeber): Attention-deficit hyperactivity disorder: A handbook for diagnosis and treatment (pp. 22–23). ↥
[Humphreys, Lee (2011): Risk Taking and Sensitivity to Punishment in Children with ADHD, ODD, ADHD+ODD, and Controls. J Psychopathol Behav Assess. 2011;33(3):299-307. doi: 10.1007/s10862-011-9237-6. PMID: 33132494; PMCID: PMC7597674.](https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7597674/ ↥
[Ritz (2009): Studying noninvasive indices of vagal control: the need for respiratory control and the problem of target specificity. Biol Psychol. 2009 Feb;80(2):158-68. doi: 10.1016/j.biopsycho.2008.08.003. PMID: 18775468.](https://pubmed.ncbi.nlm.nih.gov/18775468/ ↥
