5-HT uptake in platelets of lithium-treated patients with affective disorders and of healthy controls.

There is strong evidence that platelet 5-HT uptake is reduced during depressive illness, yet it is an open question whether this abnormality can be reverted to normal by successful treatment. The effect of longterm lithium treatment (> 2 years of continuous therapy) on 5-HT uptake of 37 euthymic affective patients without relevant additional medication was investigated. There was no difference in 5-HT uptake kinetics between the whole group of patients and age- and sex-matched healthy controls. The subgroups of unipolar patients and patients with minor recurrences during prophylaxis tended to have lower Vmax values of 5-HT uptake. The results generally support the hypothesis of a relationship between successful lithium treatment and normalization of 5-HT uptake.