The evolution of the clinical concepts regarding depressive syndromes underlines the need for correlating the epidemiological, clinical and etiopathogenic data for elaborating the classification, quantification and psychopathologic assessment systems. The psychological investigation, complementary to clinical examination and adapted to patient's subjective condition, requires an improvement of its methods in view of bringing more information necessary for stating the differential psychodiagnosis and for a proper psychotherapy. The analysis of motivations and the psychopathologic relationships in the depressive states render evident the factorial complexity and the need of a clinical, psychological, genetic, biochemical, experimental and therapeutic approach. Thus, a bio-medical and psychotherapeutic approach will improve the clinical research and psychopathologic assessment. The psychodiagnosis and psychotherapy, as elements of clinical care, make possible the clearing up of the therapeutic possibilities in the complex approach of personality, promoting the psychoprotective comprehension and the state of mental health.