Header Image
Hyperactivity in ADHD - Neurophysiological correlates

Sitemap

Hyperactivity in ADHD - Neurophysiological correlates

1. Hyperactivity primarily mediated by the striatum

Hyperactivity, as exhibited by ADHD-HI and ADHD-C, is mediated by the striatum, which is connected to the PFC via the striatofrontal dopamine circuit.1 2345678 Within the striatum, it is the nucleus accumbens in the ventral striatum that causes hyperactivity through disinhibition.910 The dorsal striatum is involved in the selection, initiation and execution of voluntary motor responses.8 Only the right hemisphere of the PFC is involved,11 which processes negative emotions (such as stress), while the left hemisphere is responsible for positive emotions.

A slight increase in dopamine (in healthy animals, i.e. exceeding the normal level) in the ventral striatum increases hyperactivity. An extreme increase in the dorsal striatum causes stereotypical behavior, as can occur in ASD10
Since the dopamine effect follows the inverted-U pattern, the reduced dopamine as a deviation from the optimal level is also responsible for hyperactivity in ADHD.

According to other sources, motor hyperactivity is modulated by a loop between prefrontal motor cortex → putamen (in the lateral striatum) → thalamus → prefrontal motor cortex.12

Dopamine degradation in the striatum occurs primarily via DAT. Polymorphisms of the DAT gene are therefore involved in hyperactivity and other symptoms mediated via the striatum.11314151617184519202122

Whether DAT in the striatum is increased, normal or decreased in ADHD is unclear.
This raises the question of how much the DAT are really involved in symptom mediation in ADHD. While on the one hand smoking can be seen as a self-medication for dopamine increase and DAT reduction, on the other hand smoking does not eliminate the ADHD symptom. Perhaps the key to resolving the apparent contradiction lies in the short-term nature of the dopaminergic effect of smoking.
An increased DAT count is associated with a reduced dopamine level in the striatum. As the DAT count is even higher in ADHD-HI than in ADHD-I, the dopamine level in ADHD-HI is even lower than in ADHD-I.
It is discussed that the reduced dopamine level due to the increased DAT count in ADHD-HI triggers hyperactivity.

As expected, rats that do not form / barely form functional DAT due to genetic manipulation have a significantly increased dopamine level in the striatum. Nevertheless, they also suffer from hyperactivity. This could still be explained by the fact that too high a neurotransmitter level triggers very similar symptoms to too low a neurotransmitter level, as the optimal neurotransmitter level required for optimal signal transmission does not exist. It is conceivable that if the dopamine level is only elevated because the dopamine is not stored again from the synaptic cleft into the vesicles due to a lack of DAT, it is present in high proportion in the synaptic cleft, but not in response to a stimulus (in order to create a common basis for decision-making together with many other nerves, by simultaneously transmitting nerve signals through the release of dopamine), but as an ever-present activation, which, like an annoying background noise on the radio, is also a noise but has nothing to do with the music being transmitted.
Treatment with amphetamine, methylphenidate, D1 receptor agonists or halperidol also reduced hyperactivity in genetically manipulated DAT-less rats.23 Hyperactivity (in addition to attention and memory problems) was also observed in mice with DAT deficiency, which was reduced by amphetamine medication. Amphetamine medication therefore also normalized the low number of DAT in the striatum.24

Adults have a significantly lower number of dopamine transporters in the striatum than children. For every 10 years of age, there is a decrease of 7 %, whereby the decrease is significantly higher up to around 40 years of age than thereafter. In 50-year-olds, the number is only about half as high as in 10-year-olds.2526

Certain “risk” polymorphisms of the DAT gene correlate more strongly with the degree of symptoms of hyperactivity and impulsivity and less with the symptoms mediated by the PFC (inattention, working memory problems), since the PFC does not regulate dopamine via DAT (but via COMT).272128
In the striatum, dopamine degradation also appears to occur through membrane-bound COMT. Mb-COMT knockout mice (mice without membrane-bound COMT) show increased dopamine levels in the striatum, but not in the PFC. This suggests that mb-COMT is involved in dopamine degradation in the striatum, whereas only soluble COMT may be involved in the PFC.29

MPH has different neurological effects depending on the dosage. Since moderate to high doses of MPH bind to DAT, moderate to high doses of MPH are effective for hyperactivity and impulsivity. This is why most people with ADHD-HI or ADHD-C respond well to moderate to high doses of MPH, while people with ADHD-I are said to benefit less from it.2730313233

At low doses, methylphenidate preferentially enhances dopaminergic neurotransmission in the PFC, from which people with ADHD-I are said to benefit significantly better.2734

However, people with ADHD of the hyperactive-impulsive type (EEG: excessively high beta) are known to achieve good results in terms of restlessness and attention with minimal doses of stimulants. Only drive and mood were only improved with higher doses.
Similarly, we know people with ADHD-I who cope very well with quite high doses of MPH. The mechanisms of action therefore appear to be more complex.

The principle of dose dependence in the effect of stimulants could correspond to the dose-dependent effect of dopamine and noradrenaline on the PFC - albeit with different results. Low elevations of dopamine and noradrenaline (as occur during manageable stress) improve PFC performance. Low-dose MPH increases dopamine and noradrenaline levels in the PFC. The effect of low-dose MPH and slightly increased dopamine / noradrenaline in the PFC is therefore concurrent.
High levels of dopamine and noradrenaline switch off the PFC.
Higher amounts of MPH continue to act on the striatum (via DAT) and no longer improve the performance of the PFC (where the few DAT are already occupied by small amounts of MPH and a higher amount of MPH therefore no longer has any positive effects).3536

Hyperactivity and impulsivity are also caused by overexpression of the Atxn7 gene in the PFC and striatum.37 In this case, atomoxetine was able to eliminate the hyperactivity and impulsivity.

Severe hyperactivity correlated in one study with38
in idle mode with increased functional connectivity:

  • In the left putamen
  • In the right caudate nucleus
  • In the right central operculum
  • In a part of the right postcentral gyrus within the auditory and sensorimotor network

2. Age-related differences in hyperactivity

The hyperactivity typical of the ADHD-HI subtype in children turns into a permanent inner restlessness in adulthood, a feeling of being driven.

2.1. Dopa decarboxylase activity

While there is a reduction in striatal and prefrontal dopa decarboxylase activity in children with hyperactivity,39 this is not reproducible in adults with ADHD-HI.40

2.2. HVA (homovanillic acid)

While several studies in boys with hyperactivity found a clear correlation to increased HVA levels in the cerebrospinal fluid, which correlated with good response to MPH and AMP,4142 43 another study in adults with ADHD-HI could not find an increase in HVA in the cerebrospinal fluid. This also suggests that persistent ADHD in adulthood has an altered pathophysiological basis.44

HVA is a degradation product of dopamine and is measured in the cerebrospinal fluid or in urine, whereby the former is considerably more complex, but allows much better conclusions to be drawn about the dopamine metabolism in the brain. A measurement in urine involves the dopamine metabolism of the entire body and is therefore not very meaningful. HVA measurements of the cerebrospinal fluid can also only reference the overall dopamine metabolism of the brain, without allowing statements to be made about the dopamine level in individual brain regions.

The finding that MPH or AMP administration is associated with a decrease in HVA in the cerebrospinal fluid of children with reduced hyperactivity could possibly be explained by a decrease in dopamine production in the substantia nigra.43

2.3. DAT

The DAT decline sharply in adulthood. As explained in section 1, the striatum plays a significant role in the neurological mediation of hyperactivity. DAT are primarily located in the striatum.
This could explain the significant change in symptoms from hyperactivity in childhood to inner restlessness and being driven.

3. Dopamine excess or dopamine deficiency cause hyperactivity

Two parallel prefrontal-striatal-thalamic-cortical circuits are involved in the control of motor reactions by the striatum.438

The “direct” way:

PFC → inner segment of the globus pallidus → thalamus → PFC

The purpose is a net amplification (by means of a disinhibition of excitatory cells of the thalamus) of the original cortical output. Dopamine deficiency in this circuit causes difficulties in movement initiation as known from Parkinson’s disease.

The “indirect” way:

The outer segment of the globus pallidus and its synapses → inhibit projections of the subthalamic nucleus to the → inner globus pallidus, causing a net inhibition of cortical dopamine production. Dopamine deficiency in this circuit causes excessive motor activity.

ADHD-HI hyperactivity can result from both dopamine deficiency and dopamine excess:45

  • Excess dopamine4647
    • In the inner segment of the globus pallidus8

or

  • Dopamine deficiency48
    • In the nucleus accumbens49
    • In the outer segment of the globus pallidus (due to insufficient inhibition)8

4. Excessively elevated beta as a possible cause of hyperactivity

A small subgroup of the mixed type exhibits genetically determined hyperactive frontal lobes with excessively increased beta activity. This neurological abnormality is not found in ADHD-I, but only in a subgroup of the mixed type, which differs from the rest of ADHD-C only by a greater tendency to tantrums, mood swings and increased delinquency.5051 People with ADHD with excessive beta are physically hyperactive (adults: inner restlessness), but not neurologically hyperactive. Typically, compared to non-affected persons52

  • Beta increased overall
  • Delta is significantly reduced centrally posteriorly
  • Alpha is reduced overall
  • Significantly reduces the overall posterior performance
  • The theta / beta ratio is reduced overall.
  • The skin conductance is significantly reduced (just like in a person with ADHD with excessively elevated theta)

Consequences are that the theta / beta ratio is not associated with arousal.52

This small group with excessively elevated beta must be distinguished from the larger group with excessively elevated theta, which corresponds more to the ADHD-I type. In this group of people with ADHD, compared to people without ADHD52

  • Total frontal power significantly increased
  • Theta significantly increased
  • Significantly increases the theta / beta ratio
  • Alpha reduced across the entire skullcap
  • Beta reduced across the entire skullcap

More on subtypes of ADHD according to EEG and QEEG at The subtypes of ADHD: ADHD-HI, ADHD-I, SCT and others And Neurofeedback as ADHD therapy.

5. Relatively low alpha

One study reports relatively low alpha, which causes problems with motor inhibition. Neurofeedback training, which subsequently increased alpha in the resting state, improved motor inhibition in ADHD.53

6. Other striatal-relevant genes as a possible cause of hyperactivity

The pseudogene Gm6180 for n-cofilin (Cfl1) is expressed 20-fold higher in hyperactive mice (bred for hyperactivity). Latrophilin 3 (Lphn3) and its ligand fibronectin-leucine-rich transmembrane protein 3 (Flrt3) are downregulated in hyperactive mice.54

Hyperactivity and impulsivity are also caused by overexpression of the Atxn7 gene in the PFC and striatum.37 In this case, atomoxetine was able to eliminate the hyperactivity and impulsivity. It is not surprising that the effectiveness of medication depends on the way in which the symptom in question is caused.

7. Zonulin increased in hyperactivity

Zonulin is a protein that controls the permeability of the intestinal wall. Elevated zonulin levels represent increased permeability of the intestinal wall.

A study of 40 people with ADHD and 41 people without ADHD found elevated zonulin levels in the people with ADHD, with the elevated zonulin levels also correlating with hyperactivity,55 so there may be a higher association with ADHD-HI than with ADHD-I.
Another study found elevated serum zonulin and occludin levels in children with ADHD.56

More about Zonulin and its effects:
Increased intestinal permeability in ADHD

8. Orexin increased with hyperactivity, decreased with hypoactivity

Orexin antagonists reduce motor hyperactivity induced by stimulants.57

9. Latrophilin-3: Gene knockout causes hyperactivity

The latrophilin-3 gene was switched off in rats. This resulted in58

  • Increase from

    • Hyperactivity
    • Weight (only for females)
    • Shock sensitivity to acoustic stimuli
    • In the striatum:
      • Dopamine transporter
      • Dopamine D1 receptor (DRD1)
      • Tyrosine hydroxylase
      • Aromatic L-amino acid decarboxylase (AADC)
  • Reduction of

    • Growth
    • Of the dopamine- and cAMP-regulated neuronal phosphoprotein (DARPP-32)
    • Activity after amphetamine administration
    • Anxiety (only in females)
  • No change from

    • DRD2
    • DRD4
    • Vesicular monoamine transporter-2
    • N-methyl-d-aspartate (NMDA)-NR1, -NR2A or -NR2B
    • Lphn1, Lphn2 and Flrt3 by qPCR and their protein products (no upregulation)
    • Reproduction
    • Survival rate

These results are consistent with studies on humans, mice, zebrafish and Drosophila.

10. NURR1 knockout causes hyperactivity and impulsivity

NURR1 is a transcription factor that regulates the dopamine signaling pathway and has a decisive influence on the development of dopaminergic neurons in the midbrain. Mice in which NURR1 was deactivated developed hyperactivity and impulsivity, but not the other ADHD symptoms such as anxiety, physical coordination problems, altered social behavior or memory problems. Neither tyrosine hydroxylase (which limits catecholamine synthesis) nor dopamine levels were altered by NURR1 blockade. The hyperactivity caused by NURR1 deactivation could be remedied by methylphenidate.59

11. Ether lipid deficiency causes hyperactivity and other ADHD symptoms

A deficiency of ether lipid (which has also been found in Alzheimer’s patients), as modeled by blocking glycerone phosphate O-acyltransferase, leads to a severe disorder of neurotransmitter balance. The symptoms observed in mice are60

  • Hyperactivity
  • Memory problems
  • Social behavior
  • Behavioral problems
  • Changed anxiety reactions
  • Depressive symptoms

Social curiosity and nesting behavior were unchanged.

The nigrostriatal dopamine level was significantly reduced, as was the number of vesicular monoamine transporters and the release of noradrenaline.61

12. Elevated homocysteine levels (e.g. due to B12 deficiency) can trigger hyperactivity

Low B12 levels correlate with increased hyperactivity/impulsivity in ADHD and Oppositional Defiant Disorder (ODD).6263 B12 deficiency can increase homocysteine levels in several ways.64 B12 deficiency (or the excessive homocysteine levels it triggers) can explain up to 13% of the hyperactivity/impulsivity symptoms of ADHD.62

13. Overexpression of the Atxn7 gene

Hyperactivity and impulsivity are also caused by overexpression of the Atxn7 gene in the PFC and striatum.37

14. Changes in pupil dilation

Pupil dilation is an indirect index of arousal that is noradrenergically modulated by the autonomic nervous system and activity in the locus coeruleus. Hyperactivity / impulsivity correlates with pupil dilation to happy faces, not to unhappy or neutral faces.65

15. Limbic system

Hyperactivity/impulsivity symptoms in ADHD correlated with an activation of the limbic system:66

16. D2 receptor - dopamine transporter - communication disorder

The D2 receptor and DAT communicate directly via certain proteins. If this communication (via certain peptides) is interrupted, mice develop pronounced motor hyperactivity.67

17. Excess dopamine synthesis

Overexpression of dUBE3A (the Drosophila homolog of UBE3A) in Drosophila

  • reduces dendritic branching68
    • dUBE3A appears to be essential for proper neuronal development
  • increases tetrahydrobiopterin [THB] (a rate-limiting cofactor for monoamine synthesis)69
  • this increases the dopamine level
    • Increase in dopamine levels causes hyperactivity (Ferdousy et al., 2011),
      The loss of dUBE3A causes69
  • Reduction of THB
  • significant reduction in the dopamine pools
    • Hypoactivity

18. D4 receptor - correlation to hyperactivity

Reports that the D4 receptor is found exclusively in the PFC in humans, but not in the striatum3570 or only in small quantities71, have been refuted by more recent studies.72

Genro reported that in the 6-OHDA-lesioned rat, which shows transient hyperactivity as well as learning and memory deficits73, locomotor hyperactivity correlates with increased D4R density in the striatum.747572 D4 receptor binding in the PFC or nucleus accumbens was not affected. The hyperactivity could be enhanced in the animals with a D4 agonist and attenuated with a D4 antagonist.76

D4-KO mice showed no hyperactivity.77

19. 5HT1B-KO

Mice without a serotonin 1B receptor show hyperactivity during the day and at night, as well as reduced anxiety behavior.78

20. Speculation: Hyperactivity as a compensatory mechanism against stress and inflammation?

It is possible that hyperactivity could be a (somewhat) healthy compensatory mechanism of the body to provoke inflammation and stress reduction.

Contrary to previous assumptions, sports do not appear to increase calorie consumption. Among the Hadza people, active hunter-gatherers in Africa, women walk an average of 8 km and men an average of 14 km a day, i.e. about as much as an American per week, but do not consume more energy per day than sedentary office workers in the USA.79808182 The Hadza are active and fit well into their 70s and 80s and are said to have neither diabetes nor heart disease.
However, high calorie expenditure through exercise shuts down stress systems and inflammatory responses, reducing the calorie expenditure that the stress responses would have caused. to use this for exercise.8183 This could be the nutritional equivalent of the long-standing finding that sports have a stress-regulating effect.84 It also sheds new light on reduced appetite the common side effect of stimulants. Speculatively, this could be an adaptive response to the body’s reduced energy expenditure due to the reduced stress response.

We therefore wonder to what extent hyperactivity as a symptom of the externalizing ADHD subtypes could possibly be a (misguided) compensatory reaction of the body, since inflammation is more common in the externalizing stress phenotype than in the internalizing ADHD-I subtype.


  1. Diamond (2014): Biologische und soziale Einflüsse auf kognitive Kontrollprozesse, die vom präfrontalen Kortex abhängen; In: Kubesch (Herausgeberin): Exekutive Funktionen und Selbstregulation – Neurowissenschaftliche Grundlagen und Transfer in die pädagogische Praxis; Huber, Seite 21

  2. Filipek Semrud-Clikeman, Steingard, Renshaw, Kennedy, Biederman (1997): Volumetric MRI analysis comparing subjects having attention-deficit hyperactivity disorder with normal controls. J.Neurology. 1997 Mar;48(3):589-601.

  3. Hynd, Hern, Novey, Eliopulos, Marshall, Gonzalez, J. J,, et al. (1993). Attention deficit-hyperactivity disorder and asymmetry of the caudate nucleus. Journal of Child Neurology, 8, 339-347.

  4. Schrimsher, Billingsley, Jackson, Moore (2002): Caudate nucleus volume asymmetry predicts attention-deficit hyperactivity disorder (ADHD) symptomatology in children. Journal of Child Neurology, 17( 12), 877-884.

  5. Soliva, Fauquet, Bidsa, Rovir, Cannona, Rilmos-Quiroga, et al (2010). Quantitative MR analysis of caudate abnormalities in pediatric ADHD: Proposal for a diagnostic test. Psychiatry Research, 182(3), 238-243.

  6. Teicher, Ito, Glod, Suber (1996): Objective measurement of hyperactivity and attentional problems in ADHD. Joumal of the American Academy of Child and Adolescent Psychiatry, 35, 334-342.

  7. Vaidya, Austin, Kirkorian, Ridlehuber, Desmond, Glover et al. (1998): Selective effects of methylphenidate in attention deficit hyperactivity disorder: A functional magnetic resonance study. Proceedings of the National Academy of Science of the United States of America, 95, 14494-14499.

  8. Solanto (2002): Dopamine dysfunction in AD/HD: integrating clinical and basic neuroscience research. Behav Brain Res. 2002 Mar 10;130(1-2):65-71.

  9. Yael, Tahary, Gurovich, Belelovsky, Bar-Gad (2019): Disinhibition of the Nucleus Accumbens Leads to Macro-Scale Hyperactivity Consisting of Micro-Scale Behavioral Segments Encoded by Striatal Activity. J Neurosci. 2019 Jul 24;39(30):5897-5909. doi: 10.1523/JNEUROSCI.3120-18.2019.

  10. Marco EM, Adriani W, Ruocco LA, Canese R, Sadile AG, Laviola G (2011): Neurobehavioral adaptations to methylphenidate: the issue of early adolescent exposure. Neurosci Biobehav Rev. 2011 Aug;35(8):1722-39. doi: 10.1016/j.neubiorev.2011.02.011. PMID: 21376076. REVIEW

  11. Casey, Castellanos, Giedd, Marsh, Hamburger, Schubert, Vauss, Vaituzis, Dickstein, Stacey, Sarfatti Rapoport (1997): Implication of right frontostriatal circuitry in response inhibition and attention-deficit/hyperactivity disorder. Journal of tile American Academy of Child andAdolescent Psychiatry}; 36, 3 74-383.

  12. Stahl (2013): Stahl’s Essential Psychopharmacology, 4. Auflage, Chapter 12: Attention deficit hyperactivity disorder and its treatment, Seite 475

  13. Barr, Feng, Wigg, Schachar, Tannock, Roberts, Malone, Kennedy (2001): 5′-Untranslated region of the dopamine D4 receptor gene and attention-deficit hyperactivity disorder. Am. J. Med. Genet., 105: 84–90. doi:10.1002/1096-8628(20010108)105:1<84::AID-AJMG1068>3.0.CO;2-Q

  14. Bedard, Schulz, Cook, Clerkin, Ivanov, Halperin, Newcorn (2010): Dopamine transporter gene variation modulates activation of striatum in youth with ADHD. Neuroimage, 15(53), 935-942.

  15. Cook (2000): Genetics of Psychiatric Disorders: Where Have We Been and Where Are We Going? American Journal of Psychiatry, 157, 1039-1040.

  16. Cook, Stein, Krasowski, Cox, Olkon, Kieffer, et al. (1995). Association of attention-deficit disorder and the dopamine transporter gene. American Journal of Human Genetics, 56, 993-998.

  17. Daly, Hawi, Fitzgerald, Gill (1999): Mapping susceptibility loci in attention deficit hyperactivity disorder: preferential transmission of parental alleles at DAT1, DBH and DRD5 to affected children. Molecular Psychiatry. 1999, Vol. 4 Issue 2, p192. 5p.

  18. Gill, Daly, Heron, Hawi, Fitzgerald (1997): Confirmation of association between attention deficit hyperactivity disorder and a dopamine transporter polymorphism. Mol Psychiatry. 1997 Jul;2(4):311-3.

  19. Shook, Brady, Lee, Kenealy, Murphy, Gaillard, VanMeter, Cook, Stein, Vaidya (2011): Effect of dopamine transporter genotype on caudate volume in childhood ADHD and controls. Am. J. Med. Genet., 156: 28–35. doi:10.1002/ajmg.b.31132

  20. Swanson, Flodman, Kennedy, Spence, Moyzis, Schuck (2000): Dopamine genes and ADHD. Neuroscience and Biobehavioural Reviews, 24( I), 21- 25.

  21. Waldman, Rowe, Abramowitz, Kozel, Mohr, Sherman, Cleveland, Sanders, Gard, Stever (1998): Association and linkage of the dopamine transporter gene and attention-deficit hyperactivity disorder in children: Heterogeneity owing to diagnostic subtype and severity. Am J Hum Genet. 1998 Dec; 63(6): 1767–1776. doi: 10.1086/302132

  22. Yang, Chan, Jing, Li, Sham, Chen (2007): A meta-analysis of association studies between the 10-repeat allele of a VNTR polymorphism in the 3′-UTR of dopamine transporter gene and attention deficit hyperactivity disorder. Am. J. Med. Genet., 144B: 541–550. doi:10.1002/ajmg.b.30453

  23. Leo, Sukhanov, Zoratto, Illiano, Caffino, Sanna, Messa, Emanuele, Esposito, Dorofeikova, Budygin, Mus, Efimova, Niello, Espinoza, Sotnikova, Hoener, Laviola, Fumagalli, Adriani, Gainetdinov (2018): Pronounced Hyperactivity, Cognitive Dysfunctions, and BDNF Dysregulation in Dopamine Transporter Knock-out Rats; J Neurosci. 2018 Feb 21;38(8):1959-1972. doi: 10.1523/JNEUROSCI.1931-17.2018.

  24. Mereu, Contarini, Buonaguro, Latte, Managò, Iasevoli, de Bartolomeis, Papaleo (2017): Dopamine transporter (DAT) genetic hypofunction in mice produces alterations consistent with ADHD but not schizophrenia or bipolar disorder. Neuropharmacology. 2017 Jul 15;121:179-194. doi: 10.1016/j.neuropharm.2017.04.037.

  25. Krause, Krause (2014): ADHS im Erwachsenenalter, Schattauer, Seite 232, mit etlichen Nachweisen

  26. Dougherty, Bonab, Spencer, Rauch, Madras, Fischman (1999): Dopamine transporter density in patients with attention deficit hyperactivity disorder. Lancet 354: 2132-2133; Article (PDF Available) in The Lancet 354(9196):2132-3 · December 1999 with 294 Reads (Stand 10/2016); DOI: 10.1016/S0140-6736(99)04030-1

  27. Diamond (2014): Biologische und soziale Einflüsse auf kognitive Kontrollprozesse, die vom präfrontalen Kortex abhängen; In: Kubesch (Herausgeberin): Exekutive Funktionen und Selbstregulation – Neurowissenschaftliche Grundlagen und Transfer in die pädagogische Praxis; Huber, Seite 22

  28. Jucaite, Fernell, Halldin, Forssberg, Farde (2005): Reduced midbrain dopamine transporter binding in male adolescents with attention-deficit/hyperactivity disorder: Association between striatal dopamine markers and motor hyperactivity; Biological Psychiatry, Volume 57, Issue 3, 1 February 2005, Pages 229-238; https://doi.org/10.1016/j.biopsych.2004.11.009

  29. Tammimaki, Aonurm-Helm, Zhang, Poutanen, Duran-Torres, Garcia-Horsman, Mannisto (2016): Generation of membrane-bound catechol-O-methyl transferase deficient mice with disctinct sex dependent behavioral phenotype. J Physiol Pharmacol. 2016 Dec;67(6):827-842.

  30. Barkley (2001): The inattentive type of ADHD as a distinct disorder. What remains to be done. Clinical Psychology: Science and Practice, 8, 489-493.

  31. Barkley, Dupaul, Mcmurray (1991). Attention deficit disorder with and without hyperactivity: Clinical response to three dose levels of methylphenidate. Pediatrics, 87, 519-531.

  32. Milich, Balentine, Lynam (2001): ADHD Combined Type and ADHD Predominantly Inattentive Type Are Distinct and Unrelated Disorders. Clinical Psychology: Science and Practice, 8: 463–488. doi:10.1093/clipsy.8.4.463

  33. Weiss, Worling, Wasdell (2003): A chart review study of the inattentive and combined types of ADHD. Journal of Attention Disorders. 7, 1-9.

  34. Berridge, Devilbiss, Andrzejewski, Arnsten, Kelley, Schmeichel, Hamilton, Spencer (2006): Methylphenidate preferentially increases catecholamine neurotransmission within the prefrontal cortex at low doses that enhance cognitive function. Biol Psychiatry. 2006 Nov 15;60(10):1111-20.

  35. Diamond (2014): Biologische und soziale Einflüsse auf kognitive Kontrollprozesse, die vom präfrontalen Kortex abhängen; In: Kubesch (Herausgeberin): Exekutive Funktionen und Selbstregulation – Neurowissenschaftliche Grundlagen und Transfer in die pädagogische Praxis; Huber, Seite 23

  36. Ishimatsu, Kidani, Tsuda, Akasu (2002): Effects of methylphenidate on the membrane potential and current in neurons of the rat locus coeruleus. J Neurophysiol. 2002 Mar;87(3):1206-12.

  37. Dela Peña, Botanas, de la Peña, Custodio, Dela Peña, Ryoo, Kim, Ryu, Kim, Cheong (2018): The Atxn7-overexpressing mice showed hyperactivity and impulsivity which were ameliorated by atomoxetine treatment: A possible animal model of the hyperactive-impulsive phenotype of ADHD. Prog Neuropsychopharmacol Biol Psychiatry. 2018 Aug 17;88:311-319. doi: 10.1016/j.pnpbp.2018.08.012.

  38. Sörös, Hoxhaj, Borel, Sadohara, Feige, Matthies, Müller, Bachmann, Schulze, Philipsen (2019): Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI. BMC Psychiatry. 2019 Jan 25;19(1):43. doi: 10.1186/s12888-019-2031-9.

  39. Ernst, Zametkin, Matochik, Jons, Cohen (1998): DOPA decarboxylase activity in attention deficit hyperactivity disorder adults. A (fluorine-18) fluorodopa positron emission tomographic study; J. Neurosci. 18, 5901-5907, 1998 zitiert nach Franck (2003): Hyperaktivität und Schizophrenie – eine explorative Studie; Dissertation, Seite 68

  40. Franck (2003): Hyperaktivität und Schizophrenie – eine explorative Studie; Dissertation, Seite 68

  41. Castellanos, Elia, Kruesi, Marsh, Gulotta, Potter, Ritchie, Hamburger, Rapoport (1996): Cerebrospinal fluid homovanillic acid predicts behavioral response to stimulants in 45 boys with attention deficit/hyperactivity disorder. Neuropsychopharmacology. 1996 Feb;14(2):125-37.

  42. Castellanos, Elia, Kruesi, Gulotta, Mefford, Potter, Ritchie, Rapoport (1994): Cerebrospinal fluid monoamine metabolites in boys with attention-deficit hyperactivity disorder. Psychiatry Res. 1994 Jun;52(3):305-16.

  43. Castellanos (1997): Toward a pathophysiology of attention-deficit/hyperactivity disorder. Clin Pediatr (Phila). 1997 Jul;36(7):381-93.

  44. Ernst, Liebenauer, Tebeka, Jons, Eisenhofer, Murphy, Zametkin (1997): Selegiline in ADHD adults: Plasma monoamine and monoamine metabolites. Neuropsychopharmacology 16, 276-284, 1997, zitiert nach Franck (2003): Hyperaktivität und Schizophrenie – eine explorative Studie; Dissertation, Seite 68

  45. Castellanos, Tannock (2002): Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes. Nat Rev Neurosci. 2002 Aug;3(8):617-28. doi: 10.1038/nrn896. PMID: 12154363.

  46. Giros, Jaber, Jones, Wightman, Caron (1996): Hyperlocomotion and indifference to cocaine and amphetamine in mice lacking the dopamine transporter. Nature. 1996 Feb 15;379(6566):606-12. doi: 10.1038/379606a0. PMID: 8628395.

  47. Viggiano, Grammatikopoulos, Sadile (2002): A morphometric evidence for a hyperfunctioning mesolimbic system in an animal model of ADHD. Behav Brain Res. 2002 Mar 10;130(1-2):181-9. doi: 10.1016/s0166-4328(01)00423-5. PMID: 11864733.

  48. Shaywitz, Yager, Klopper (1976): Selective brain dopamine depletion in developing rats: an experimental model of minimal brain dysfunction. Science. 1976 Jan 23;191(4224):305-8. doi: 10.1126/science.942800. PMID: 942800.

  49. Cardinal, Pennicott, Sugathapala, Robbins, Everitt (2001): Impulsive choice induced in rats by lesions of the nucleus accumbens core. Science. 2001 Jun 29;292(5526):2499-501. doi: 10.1126/science.1060818. PMID: 11375482.

  50. Clarke, Barry, McCarthy, Selikowitz (2001): Excess beta in children with attention-deficit/hyperactivity disorder: an atypical electrophysiological group. Psychiatry Research, 103, 205-218.

  51. Clarke, Barry, Dupuy, Heckel, McCarthy, Selikowitz, Johnstone (2011): Behavioural differences between EEG-defined subgroups of children with attention-deficit/hyperactivity disorder. Clinical Neurophysiology, 122, 1333-1341.

  52. Clarke, Barry, Dupuy, McCarthy, Selikowitz, Johnstone (2013). Excess beta activity in the EEG of children with attention-deficit/hyperactivity disorder: a disorder of arousal? International Journal of Psychophysiology, 89, 314-319

  53. Deiber, Hasler, Colin, Dayer, Aubry, Baggio, Perroud, Ros (2019): Linking alpha oscillations, attention and inhibitory control in adult ADHD with EEG neurofeedback. Neuroimage Clin. 2019 Dec 24;25:102145. doi: 10.1016/j.nicl.2019.102145.

  54. Sorokina, Saul, Goncalves, Gogola, Majdak, Rodriguez-Zas, Rhodes (2018): Striatal transcriptome of a mouse model of ADHD reveals a pattern of synaptic remodeling. PLoS One. 2018 Aug 15;13(8):e0201553. doi: 10.1371/journal.pone.0201553. eCollection 2018.

  55. Özyurt, Öztürk, Appak, Arslan, Baran, Karakoyun, Tufan, Pekcanlar (2018): Increased zonulin is associated with hyperactivity and social dysfunctions in children with attention deficit hyperactivity disorder. Compr Psychiatry. 2018 Nov;87:138-142. doi: 10.1016/j.comppsych.2018.10.006. n = 81

  56. Çakir A, Dogru H, Laloglu E (2023): Serum Occludin and Zonulin Levels in Children With Attention-Deficit/Hyperactivity Disorder and Healthy Controls. Indian Pediatr. 2023 Feb 15;60(1):137-141. PMID: 36786182.

  57. Gentile, Simmons, Watson, Connelly, Brailoiu, Zhang, Muschamp (2018): Effects of Suvorexant, a Dual Orexin/Hypocretin Receptor Antagonist, on Impulsive Behavior Associated with Cocaine. Neuropsychopharmacology. 2018 Apr;43(5):1001-1009. doi: 10.1038/npp.2017.158.

  58. Regan, Hufgard, Pitzer, Sugimoto, Hu, Williams, Vorhees (2019): Knockout of latrophilin-3 in Sprague-Dawley rats causes hyperactivity, hyper-reactivity, under-response to amphetamine, and disrupted dopamine markers. Neurobiol Dis. 2019 Jun 6:104494. doi: 10.1016/j.nbd.2019.104494.

  59. Montarolo, Martire, Perga, Spadaro, Brescia, Allegra, De Francia, Bertolotto (2019): NURR1 deficiency is associated to ADHD-like phenotypes in mice. Transl Psychiatry. 2019 Aug 27;9(1):207. doi: 10.1038/s41398-019-0544-0.

  60. Dorninger, Gundacker, Zeitler, Pollak, Berger (2019): Ether Lipid Deficiency in Mice Produces a Complex Behavioral Phenotype Mimicking Aspects of Human Psychiatric Disorders. Int J Mol Sci. 2019 Aug 13;20(16). pii: E3929. doi: 10.3390/ijms20163929.

  61. Dorninger, König, Scholze, Berger, Zeitler, Wiesinger, Gundacker, Pollak, Huck, Just, Forss-Petter, Pifl, Berger (2019): Disturbed neurotransmitter homeostasis in ether lipid deficiency. Hum Mol Genet. 2019 Jun 15;28(12):2046-2061. doi: 10.1093/hmg/ddz040.

  62. Yektaş, Alpay, Tufan (2019): Comparison of serum B12, folate and homocysteine concentrations in children with autism spectrum disorder or attention deficit hyperactivity disorder and healthy controls. Neuropsychiatr Dis Treat. 2019 Aug 6;15:2213-2219. doi: 10.2147/NDT.S212361. eCollection 2019.

  63. Saha, Chatterjee, Verma, Ray, Sinha, Rajamma, Mukhopadhyay (2018): Genetic variants of the folate metabolic system and mild hyperhomocysteinemia may affect ADHD associated behavioral problems. Prog Neuropsychopharmacol Biol Psychiatry. 2018 Jun 8;84(Pt A):1-10. doi: 10.1016/j.pnpbp.2018.01.016.

  64. Pusceddu, Herrmann, Kleber, Scharnagl, März, Herrmann (2019): Telomere length, vitamin B12 and mortality in persons undergoing coronary angiography: the Ludwigshafen risk and cardiovascular health study. Aging (Albany NY). 2019 Sep 6;11(17):7083-7097. doi: 10.18632/aging.102238.

  65. Kleberg, Frick, Brocki (2020): Increased pupil dilation to happy faces in children with hyperactive/impulsive symptoms of ADHD. Dev Psychopathol. 2020 Feb 27:1-11. doi: 10.1017/S0954579420000036. PMID: 32102703. n = 71

  66. Jakobi, Arias-Vasquez, Hermans, Vlaming, Buitelaar, Franke, Hoogman, van Rooij (2022): Neural Correlates of Reactive Aggression in Adult Attention-Deficit/Hyperactivity Disorder. Front Psychiatry. 2022 May 19;13:840095. doi: 10.3389/fpsyt.2022.840095. PMID: 35664483; PMCID: PMC9160326.

  67. Lee, Pei, Moszczynska, Vukusic, Fletcher, Liu (2007): Dopamine transporter cell surface localization facilitated by a direct interaction with the dopamine D2 receptor. EMBO J. 2007;26(8):2127–2136. doi:10.1038/sj.emboj.7601656

  68. Lu Y, Wang F, Li Y, Ferris J, Lee JA, Gao FB (2009): The Drosophila homologue of the Angelman syndrome ubiquitin ligase regulates the formation of terminal dendritic branches. Hum Mol Genet. 2009 Feb 1;18(3):454-62. doi: 10.1093/hmg/ddn373. PMID: 18996915; PMCID: PMC2638802.

  69. Ferdousy F, Bodeen W, Summers K, Doherty O, Wright O, Elsisi N, Hilliard G, O’Donnell JM, Reiter LT (2011): Drosophila Ube3a regulates monoamine synthesis by increasing GTP cyclohydrolase I activity via a non-ubiquitin ligase mechanism. Neurobiol Dis. 2011 Mar;41(3):669-77. doi: 10.1016/j.nbd.2010.12.001. Epub 2010 Dec 13. PMID: 21147225; PMCID: PMC3040417.

  70. Meador-Woodruff, Damask, Wang, Haroutunian, Davis, Watson (1996): Dopamine receptor mRNA expression in human striatum and neocortex; Neuropsychopharmacology. 1996 Jul;15(1):17-29.

  71. Noaín D, Avale ME, Wedemeyer C, Calvo D, Peper M, Rubinstein M (2006): Identification of brain neurons expressing the dopamine D4 receptor gene using BAC transgenic mice. Eur J Neurosci. 2006 Nov;24(9):2429-38. doi: 10.1111/j.1460-9568.2006.05148.x. PMID: 17100831.

  72. Ferré S, Belcher AM, Bonaventura J, Quiroz C, Sánchez-Soto M, Casadó-Anguera V, Cai NS, Moreno E, Boateng CA, Keck TM, Florán B, Earley CJ, Ciruela F, Casadó V, Rubinstein M, Volkow ND (2022): Functional and pharmacological role of the dopamine D4 receptor and its polymorphic variants. Front Endocrinol (Lausanne). 2022 Sep 30;13:1014678. doi: 10.3389/fendo.2022.1014678. PMID: 36267569; PMCID: PMC9578002. REVIEW

  73. Archer T, Danysz W, Fredriksson A, Jonsson G, Luthman J, Sundström E, Teiling A (1988): Neonatal 6-hydroxydopamine-induced dopamine depletions: motor activity and performance in maze learning. Pharmacol Biochem Behav. 1988 Oct;31(2):357-64. doi: 10.1016/0091-3057(88)90358-9. PMID: 3149743.

  74. Avale ME, Falzone TL, Gelman DM, Low MJ, Grandy DK, Rubinstein M (2004): The dopamine D4 receptor is essential for hyperactivity and impaired behavioral inhibition in a mouse model of attention deficit/hyperactivity disorder. Mol Psychiatry. 2004 Jul;9(7):718-26. doi: 10.1038/sj.mp.4001474. PMID: 14699433.

  75. Genro JP, Kieling C, Rohde LA, Hutz MH (2010): Attention-deficit/hyperactivity disorder and the dopaminergic hypotheses. Expert Rev Neurother. 2010 Apr;10(4):587-601. doi: 10.1586/ern.10.17. PMID: 20367210. REVIEW

  76. Zhang K, Davids E, Tarazi FI, Baldessarini RJ (2002): Effects of dopamine D4 receptor-selective antagonists on motor hyperactivity in rats with neonatal 6-hydroxydopamine lesions. Psychopharmacology (Berl). 2002 Apr;161(1):100-6. doi: 10.1007/s00213-002-1018-1. PMID: 11967637.

  77. Helms CM, Gubner NR, Wilhelm CJ, Mitchell SH, Grandy DK (2008): D4 receptor deficiency in mice has limited effects on impulsivity and novelty seeking. Pharmacol Biochem Behav. 2008 Sep;90(3):387-93. doi: 10.1016/j.pbb.2008.03.013. PMID: 18456309; PMCID: PMC2603181.

  78. Brunner D, Buhot MC, Hen R, Hofer M (1999): Anxiety, motor activation, and maternal-infant interactions in 5HT1B knockout mice. Behav Neurosci. 1999 Jun;113(3):587-601. doi: 10.1037//0735-7044.113.3.587. PMID: 10443785.

  79. Pontzer (2017): The crown joules: energetics, ecology, and evolution in humans and other primates. Evol Anthropol. 2017 Jan;26(1):12-24. doi: 10.1002/evan.21513. PMID: 28233387.

  80. Pontzer, Wood (2021): Effects of Evolution, Ecology, and Economy on Human Diet: Insights from Hunter-Gatherers and Other Small-Scale Societies. Annu Rev Nutr. 2021 Oct 11;41:363-385. doi: 10.1146/annurev-nutr-111120-105520. PMID: 34138633.

  81. Gibbons (2022): The calorie counter. Science. 2022 Feb 18;375(6582):710-713. doi: 10.1126/science.ada1185. PMID: 35175814.

  82. Dugas, Harders, Merrill, Ebersole, Shoham, Rush, Assah, Forrester, Durazo-Arvizu, Luke (2011): Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies. Am J Clin Nutr. 2011 Feb;93(2):427-41. doi: 10.3945/ajcn.110.007278. PMID: 21159791; PMCID: PMC3021434. METASTUDIE

  83. Tsatsoulis, Fountoulakis (2006): The protective role of exercise on stress system dysregulation and comorbidities. Ann N Y Acad Sci. 2006 Nov;1083:196-213.

  84. Fuchs, Gerber (Hrsg.): Handbuch Stressregulation und Sport, S. 205–226