Background: Previous study shows that cellular immunity and family relationships are each correlated with the severity of depression and suggests that the psycho-immunological theory should look at the relation between immunity and family life. The aim of the present study based on the same sample is to investigate if similar correlations exist with humoral immunity.
Subjects and method: 498 inpatients with major depressive disorder were enrolled in an open-label trial. In addition to a socio- demographic questionnaire, they completed Olsen's FACES III and the Beck Depression Inventory (BDI). We performed a classic blood test, a plasma cortisol assay at 8 a.m., 4 p.m. and 8 p.m. and a dexamethasone suppression test (Carroll test). Electrophoresis is used for separation and quantification of serum proteins.
Results: There is no correlation between humoral immunity and the severity of depression. We found a correlation between cohesion of the family of the origin and beta-globulins (r=-0.147; p=0.016), and C4 (r=0.124; p=0.039). Between adaptability of the family of the origin and cortisol levels at 8 a.m. (r=0.122; p=0.008). We showed a correlation between both C4 (r=-0.263; p=0.000) and beta-globulins (r=-0.148; p=0.013) with CD8. There is a correlation between cortisol at 8 a.m. and CD4 (r=-0.095; p=0.033).
Conclusions: Humoral immunity has no correlation with depression but has multiple interactions with cellular immunity which is correlate with the severity of the depression. The psycho-immunological theory is reinforced. It is quite original to find correlation between the family functioning and C4 or beta-globulins while the link with cortisol strengthens some studies about psychological stress, cortisol and immunity. Future studies should examine which kind of family or relation are implicated and how the family functioning and immunity could be connected.