Acute tryptophan depletion. Part II: clinical effects and implications.
OBJECTIVE
This is the second of two articles reviewing the modern dietary technique of acute tryptophan depletion (ATD), a method of transiently reducing central serotonin levels in both healthy volunteers and clinical populations. This article details the clinical studies to date and discusses the implications of this research methodology.


METHODS
The authors present a review of clinical ATD studies collated from a MEDLINE search, unpublished communications and the authors' considerable experience with this paradigm.


RESULTS
Following from the initial use of ATD in subjects with depressive illness, studies of anxiety disorders and other psychiatric illnesses have been reported. Sleep, aggressive and cognitive effects are also active areas of research and are reviewed here.


CONCLUSIONS
Acute tryptophan depletion remains a useful psychiatric research tool. The findings from the clinical studies reviewed here are summarized and implications for future research detailed.
Department of Psychological Medicine, Christchurch School of Medicine and Health Sciences, New Zealand.
Caroline J
CJ
Bell
Sean D
SD
Hood
David J
DJ
Nutt
D000483:Alleles; D000544:Alzheimer Disease / Q000378:metabolism; D001321:Autistic Disorder / Q000378:metabolism; D001714:Bipolar Disorder / Q000378:metabolism; D015928:Cognitive Behavioral Therapy / Q000379:methods; D003865:Major Depressive Disorder / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000378:metabolism; D001068:Feeding and Eating Disorders / Q000378:metabolism; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D011293:Premenstrual Syndrome / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012559:Schizophrenia / Q000378:metabolism; D012701:Serotonin / Q000235:genetics / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000378:metabolism; D012895:Sleep, REM / Q000502:physiology; D011795:Surveys and Questionnaires; D014364:Tryptophan / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism
D006897:Hydroxyindoleacetic Acid; D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors; D014364:Tryptophan