Evaluation of immune parameters in depressed patients

The association between depression and altered immunological activities has repeatedly been suggested, but experimental data show contradictory results. In this work, cellular and humoral immunological activities were evaluated in patients presenting major depression, unipolar subtype. Natural killer cell activity (NKCA) was significantly reduced in patients as compared to healthy controls (p < 0.001). However, lymphocyte mitogenic responses and immunoglobulin titers (IgG, IgM, and IgA) were similar for all samples. Hematological, hormonal, and nutritional variables presented normal values in patients and in controls. A familial history of depression was related to lower NKCA and higher phytohemagglutinin responses (p < 0.01). These data suggest possible differential inhibition of cellular immune responses in depressed patients.