Blood coagulation and platelet aggregation in major depression.

Recently, it was found that the plasma of depressed patients significantly reduced the primary and secondary platelet aggregation to aggregating agents, such as ADP and collagen, in platelet rich plasma (PRP) of normal volunteers. Other authors found significantly decreased maximum amplitudes of adrenaline-induced platelet aggregation in major depressed patients versus normal controls. The aim of the present study was to examine platelet aggregation and blood coagulation in depression. Toward this end, the authors have measured secondary platelet aggregation to ADP and collagen, and the activated partial thromboplastin time (APTT) and prothrombin time (PT) in 16 normal volunteers, 16 minor, 40 simple major and 23 melancholic subjects. There were no significant differences in ADP- or collagen-induced platelet aggregability, APTT or PT between normal controls, minor, simple major or melancholic depressed patients. There were no significant relationships between severity of depression and APTT, PT or platelet aggregability to ADP or collagen. It is concluded that blood coagulation and platelet aggregability to ADP and collagen are probably not disordered in major depression.