title: The impact of acute tryptophan depletion on attentional performance in adult patients with ADHD.
abstract: OBJECTIVE
  To date, the impact of the neurotransmitter serotonin (5-HT) on different neuropsychological functions in adults with attention deficit hyperactivity disorder (ADHD) is underinvestigated. We aimed to examine the effects of acute tryptophan depletion (ATD) and the resulting reduction in central nervous 5-HT synthesis on target/non-target discrimination ability and sustained attention in adults with ADHD using an AX-Continuous Performance Test (AX-CPT).
  
  
  METHODS
  Twenty male patients with ADHD (age: M = 30.25 SD = 9.37) and twenty male healthy controls (age: M = 27.90 SD = 6.01) received ATD on one day and a tryptophan-balanced control condition (BAL) on another day in a double-blind within-subject crossover design. A continuous performance test (AX-CPT) with three conditions (AX, AY, and BX) was administered on both days under depleted and sham-depleted conditions.
  
  
  RESULTS
  In patients omissions increased after ATD when compared with BAL. Patient's reaction time decreased after ATD when compared with BAL, which was contrasted by opposite effects in controls. Patients showed fewer correct responses (AX condition) and showed a higher rate of errors (condition AXE ) independent of ATD or BAL intake.
  
  
  CONCLUSIONS
  The present preliminary results are indicative of the contribution of serotonergic neurotransmission to attentional processes in adults with ADHD.
authors: Department of Psychiatry and Psychotherapy, LVR Clinics Essen, University of Duisburg-Essen, Essen, Germany. christian.mette@lvr.de
authors: C
authors: C
authors: Mette
authors: M
authors: M
authors: Zimmermann
authors: M
authors: M
authors: Grabemann
authors: M
authors: M
authors: Abdel-Hamid
authors: J
authors: J
authors: Uekermann
authors: C S
authors: CS
authors: Biskup
authors: J
authors: J
authors: Wiltfang
authors: F D
authors: FD
authors: Zepf
authors: B
authors: B
authors: Kis
mesh_terms: D000328:Adult; D001288:Attention / Q000187:drug effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000378:metabolism / Q000523:psychology / Q000628:therapy; D002490:Central Nervous System / Q000378:metabolism; D018592:Cross-Over Studies; D004035:Diet Therapy / Q000379:methods*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D011580:Psychological Techniques; D011619:Psychotropic Drugs / Q000378:metabolism / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects; D012701:Serotonin / Q000096:biosynthesis*; D012737:Sex Factors; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome; D014364:Tryptophan / Q000378:metabolism / Q000494:pharmacology
chemical_list: D011619:Psychotropic Drugs; D012701:Serotonin; D014364:Tryptophan
keywords: ADHD; AX-CPT; acute tryptophan depletion; attention; serotonin