Platelet 3H imipramine binding: a possible predictor of response to antidepressant treatment.

No significant difference in the density (Bmax) of platelet 3H imipramine recognition sites were found between the group of 20 unmedicated depressed patients and 10 healthy volunteers. The mean KD value was significantly higher in the population of depressives than in controls. Non-responders (after 2 weeks of treatment with antidepressants) had significantly lower initial Bmax values than responders or control subjects. Density of platelet 3H imipramine site may thus be a predictor of early response to antidepressant therapy. No significant sex differences were found in KD or Bmax values in the depressed group or in control subjects. There was, however, a seasonal variation in Bmax but not in KD values of platelet 3H imipramine binding.