Send to

Choose Destination
See comment in PubMed Commons below
Psychol Med. 2002 Apr;32(3):503-15.

Cognition following acute tryptophan depletion: difference between first-degree relatives of bipolar disorder patients and matched healthy control volunteers.

Author information

Brain and Behaviour Institute, Department of Psychiatry and Neuropsychology, Universiteit Maastricht, The Netherlands.



Serotonergic circuits have been proposed to mediate cognitive processes, particularly learning and memory. Cognitive impairment is often seen in bipolar disorders in relation to a possible lowered serotonergic turnover.


We investigated the effects of acute tryptophan depletion (ATD) on cognitive performance in healthy first-degree relatives of bipolar patients (FH) (N= 30) and matched controls (N= 15) in a placebo-controlled, double-blind cross-over design. Performance on planning, memory and attention tasks were assessed at baseline and 5 h after ATD.


Following ATD, speed of information processing on the planning task was impaired in the FH group but not in the control group. FH subjects with a bipolar disorder type I relative (FH I) showed impairments in planning and memory, independent of ATD. In all subjects, ATD impaired long-term memory performance and speed of information processing. ATD did not affect short-term memory and focused and divided attention.


The results suggest serotonergic vulnerability affecting frontal lobe areas in FH subjects, indicated by impaired planning. Biological vulnerability in FH I subjects is reflected in impaired planning and memory performance. In conclusion, the cognitive dysfunctions in FH subjects indicate an endophenotype constituting a possible biological marker in bipolar psychopathology. Serotonin appears to be involved in speed of information processing, verbal and visual memory and learning processes.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center