Psychological Medicine

Research Article

The treatment of depression in general practice: a comparison of L-tryptophan, amitriptyline, and a combination of L-tryptophan and amitriptyline with placebo

Joan Thomson c1, H. Rankin c2, G. W. Ashcroft c3, Celia M. Yates c4, Judith K. McQueen c4 and S. W. Cummings c5


One hundred and fifteen patients from 5 general practices participated in a 12-week, double-blind study comparing L-tryptophan, amitriptyline, L-tryptophan–amitriptyline combination and placebo in the treatment of depression. Analysis of total score on the Hamilton Depression Scale and a global rating of depression showed that all 3 active treatments were more effective than placebo. Significantly more patients were withdrawn as treatment failures in the placebo group compared with the active treatment groups. Side-effects necessitated withdrawal of more patients from the amitriptyline group than from the other active tratment groups, but this difference was not significant. Plasma amitriptyline and nortriptyline levels were similar in the difference was not significant. Plasma amitriptyline and nortriptyline and biochemical profiles did not alter significantly in any group, but mean heart rate was significantly increased in patients receiving amitriptyline. There was no change in free or total plasma tryptophan concentration with treatment or on remission of symptoms.


c1 Address for correspondence: Dr Joan Thomson, Bangour Village Hospital, Dechmont, west Lothian EH52 6LW

c2 Stockbridge Health Centre, I India Place, Edinburgh

c3 Department of Mental Health, University Medical Buildings, Foresterhill, Aberdeen

c4 MRC Brain Metabolism Unit, George Square, Edinburgh

c5 Berk Pharmaceuticals Ltd, St Leonards House, St Leonards Road, Eastbourne, Sussex