<prompt> The technique of Psychological autopsy is useful in studying the causation ofSchizophreniaPersonality disordersDrug dependenceSuicide  <response>: Etiology: Some of the common causes of suicide are: Psychiatric Disorders are a major cause of suicide. Some common causes are: Depression: Major depression Depression secondary to serious physical illness. Reactive depression, secondary to life stressors, e.g. family andor marital disputes, failure in goal achievement, occupational and financial difficulties, and death of significant others. Alcoholism and drug dependence Schizophrenia Genetic factors a concordance rate of 18 in monozygotic twins and biochemical factors low levels of 5-HIAA are impoant in some case of suicide. 