Platelet 3H-imipramine binding sites in depressed patients and healthy controls: a comparison between morning and afternoon samples.

Platelet 3H-imipramine binding was compared between 19 hospitalized, depressed patients and age-matched controls (n = 11). For each individual person blood samples were withdrawn at 8 a.m. and 3 p.m. on two separate occasions (day 0 and day 28). Mean Bmax and Kd values did not differ between depressed patients and healthy controls at any of the four time-points tested, and no significant differences could be established between the different time-points, though there were irregular intraindividual variations.