Platelet [3H]imipramine binding (Bmax) was determined in 67 patients
with major affective illness (33 euthymic bipolar, 34 depressed unipolar)
and 58 normal control subjects. Bipolar patients had significantly lower
Bmax values than did control subjects. The mean Bmax in the unipolar
patients was lower than in the control subjects, but the difference was not
statistically significant. Dissociation constant (Kd) values did not
distinguish patients in either category from control subjects. The
significantly lower Bmax in euthymic bipolar patients and the apparent
state independence of Bmax in some but not all unipolar patients suggest
that platelet imipramine binding may be a trait marker in a subset of
affective disorders.Abstract Teaser