Diurnal and circannual variation in platelet 3H-imipramine binding: comparative data on normal and affectively ill subjects.

Using a cross-sectional design, we examined the diurnal and circannual variation in platelet 3H-imipramine binding in 33 patients with bipolar affective disorder, 34 patients with unipolar affective disorder and 58 normal controls. There was no evidence for statistically significant diurnal or circannual variation in the binding parameters in any of the diagnostic categories.