Lower 3H-imipramine binding in platelets from untreated depressed patients compared to healthy controls.

3H-Imipramine binding in platelets was measured in 63 severely depressed hospitalized patients, who had been drug free (with the exception of moderate doses of benzodiazepines) for at least 1 month, and in 53 healthy control subjects of comparable age and sex distribution. Bmax of 3H-imipramine binding was significantly lower in the depressed subjects (1012 +/- SD 295 vs. 1123 +/- SD 178 fmole/mg protein). Depressed patients who had attempted suicide by violent means tended to have higher Bmax than nonviolent attempters.