The work covers the study of the formation of suicidal behavior in young adults with depressive disorders and developing of pathogenetic based system of its prevention. There were clinical and psychopathological signs of depressive disorders in young patients analyzed. Anxiety, asthenia, asthenic-apathetic and melancholy variants of depressive disorders in young patients with suicidal behavior were highlighted. In this study, there were the markers of suicide risk for young patients with depressive disorders determined: high suicide risk, low death self-consciousness, high anhedonia level, clinical manifestations of anxiety and depression by the hospital anxiety and depression scale, severe anxiety and depression by the Hamilton anxiety rating scale, major depressive episode by the Montgomery-Asberg depression rating scale. It has been proved that in observed young patients with depressive disorders with suicide behavior increased concentrations of serotonin, cortisol, noradrenaline and decreased levels of adrenaline and melatonine in plasma were observed. These changes were determined as neurohormonal background for depletion of adaptation resource in stress situations. There were approaches to differentiated prevention of suicidal behavior in depressive disorders in young people validated that include pharmacotherapy (selective SSRI, melatonin, serotonin and norepinephrine), psychotherapy and psychoeducation. Psychotherapeutic complexin patients with depressive episode must include personality-oriented psychotherapy, cognitive behavioral therapy, family therapy and autogenous training; in disorders of adaptation – rational psychotherapy, cognitive-behavioral analytic psychotherapy, family therapy, autogenic training. Psychoeducation should be carried out using information modules, training a positive self-image, improved compliance; formation of communication skills, problem solving, interpersonal interaction and problem-oriented discussions.