Impaired lymphocyte function in depressive illness.

Mood states and immunity may be related. To investigate the immune status of patients with primary depressive illness, we compared in-vitro lymphocytic responses to three different mitogens in 26 drug-free depressed patients and 20 normal controls of comparable age and sex. We observed a generalized and marked decrease in the lymphocyte mitogenic activity among the depressive group. This defect in lymphocyte function may be indicative of an impairment in cell-mediated immunity in patients with primary depressive illness.