Serotonergic neurotransmission and lapses of attention in children and adolescents with attention deficit hyperactivity disorder: availability of tryptophan influences attentional performance.
Deficiencies in serotonergic (5-HT) neurotransmission have frequently been linked to altered attention and memory processes. With attention deficit hyperactivity disorder (ADHD) being associated with impaired attention and working memory, this study investigated the effects of a diminished 5-HT turnover achieved by rapid tryptophan depletion (RTD) on attentional performance in children and adolescents with ADHD. Twenty-two male patients with ADHD (aged 9-15 yr) received the RTD procedure Moja-De and a tryptophan (Trp)-balanced placebo (Pla) in a randomized, double-blind, within-subject crossover design on two separate study days. Lapses of attention (LA) and phasic alertness (PA) were assessed within the test battery for attentional performance under depleted and sham-depleted conditions 120 (T1), 220 (T2) and 300 (T3) min after intake of RTD/Pla. At T1 there was a significant main effect for RTD, indicating more LA under intake of a Trp-balanced Pla compared to diminished 5-HT neurotransmission. For T2/T3 there were no such effects. PA was not affected by the factors RTD/Pla and time. Interactions of 5-HT with other neurotransmitters as possible underlying neurochemical processes could be subject to further investigations involving healthy controls as regards altered attentional performance in children and adolescents.
Zepf
Florian D
FD
Department of Child and Adolescent Psychiatry and Psychotherapy, RWTH University of Aachen, Germany. fzepf@ukaachen.de
Gaber
Tilman J
TJ
Baurmann
David
D
Bubenzer
Sarah
S
Konrad
Kerstin
K
Herpertz-Dahlmann
Beate
B
Stadler
Christina
C
Poustka
Fritz
F
Wöckel
Lars
L
D000293:Adolescent; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000378:metabolism* / Q000523:psychology*; D002490:Central Nervous System / Q000378:metabolism; D002648:Child; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D012701:Serotonin / Q000378:metabolism*; D018490:Serotonin Agents / Q000378:metabolism; D009435:Synaptic Transmission; D013997:Time Factors; D014364:Tryptophan / Q000378:metabolism*
D018490:Serotonin Agents; D012701:Serotonin; D014364:Tryptophan