Article Text

Download PDFPDF
L-tryptophan and depressive illness


Some drugs which lower the concentration of amines in brain may produce depressive symptoms in man. An example of such a drug is reserpine which has been shown to lower the concentration of 5-hydroxytryptamine (5HT) in the brain.1 Recent studies of depressive illnesses suggest that, in some depressed patients, the cerebral content of 5HT (as reflected by CSF metabolites) is low, probably due more to a low rate of synthesis2 than to increased degradation.3 If reduced brain-5HT is a contributory factor in some depressive illnesses, restoring normal concentrations by promoting synthesis or reducing degradation should ameliorate the illness. However, evidence inconsistent with this hypothesis already exists.4 Furthermore, lack of detailed knowledge of the function of 5HT in the neurones which contain it makes accurate prediction from the animal laboratory to the psychiatric clinic difficult.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.