Effects of tryptophan depletion on reactive aggression and aggressive decision-making in young people with ADHD.
OBJECTIVE
The neurotransmitter serotonin (5-HT) has been linked to the underlying biological processes related to aggressive behaviour. However, only a few studies on this subject involving young people have been published so far.


METHODS
We aimed to investigate the effects of acute tryptophan depletion (ATD) on reactive aggression and decision-time for aggressive responses in a sample of young people with Attention deficit hyperactivity disorder (n = 20), a population at risk for aggressive behaviour. The study design was a double-blind within-subject crossover design. Aggression was assessed using a Point subtraction aggression game (PSAG) with high (HP) and low provocation (LP) trials 2.5 h after the intake of ATD and a tryptophan-balanced control condition.


RESULTS
A chi-square comparison was used to identify the effect of ATD on increased aggression after LP. Boys were more likely to respond with an increased aggressive response after HP under ATD as represented by an increased relative risk and odds ratios. Girls had a higher relative risk than boys of an increased point subtraction under ATD after LP. No significant gender differences in decision-time were detected.


CONCLUSIONS
An effect of ATD on increased aggression was found in the whole sample after LP. Research involving larger samples is needed to confirm the present preliminary findings.
Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany.
W F
WF
Kötting
S
S
Bubenzer
K
K
Helmbold
A
A
Eisert
T J
TJ
Gaber
F D
FD
Zepf
D000293:Adolescent; D000374:Aggression / Q000187:drug effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000378:metabolism / Q000523:psychology / Q000628:therapy; D002648:Child; D002652:Child Behavior / Q000187:drug effects; D018592:Cross-Over Studies; D003657:Decision Making / Q000187:drug effects; D004035:Diet Therapy / Q000379:methods; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D011580:Psychological Techniques; D011619:Psychotropic Drugs / Q000378:metabolism / Q000494:pharmacology; D012701:Serotonin / Q000096:biosynthesis*; D012737:Sex Factors; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome; D014364:Tryptophan / Q000378:metabolism / Q000494:pharmacology
D011619:Psychotropic Drugs; D012701:Serotonin; D014364:Tryptophan