the concept of the formation of mental illnesses, which assumes the existence of increased vulnerability (predisposition) in relation to specific environmental stressors in some individuals. Exposure to these stressors dramatically increases the likelihood of affective and behavioural disorders in vulnerable individuals. Thus, the concepts of stress diathesis of suicidal behavior, alcohol and drug addiction, depressive disorders, and schizophrenia have been developed and experimentally confirmed. That is, the basic idea of the concept is that some people, due to their biological, temperamental and/or behavioral characteristics, are more vulnerable (predisposed to “diathesis”) to the adverse effects of negative experiences (“stress”), while others are relatively resistant to environmental stressors.