Chapter 17: the natures and causes of mental disorders. Classif ication of d iagnosis of mental d isorders. Emil kraepelin: created the first comprehensive classification system of psychological disorders. Abnormal refers to any departure of the norm. Most important feature of a mental disorder is not whether a person"s behavior is abnormal, but whether it is maladaptive. Mental disorders are caused by the interaction of hereditary, cognitive, and environmental factors. Freud: mental disorders originate in intrapsychic conflict produced by the three components of the mind the id, ego, and superego. For some, the conflicts become so severe that the mind"s defense mechanisms cannot produce a resolution that is enough for mental health. The resultant is the defense mechanisms distort reality. Psychodynamic therapists attempt to make their clients aware of their intrapsychic conflict and defense mechanism failures to regain mental health. H ippocrates: believed that excesses of the four humors (black bile, yellow bile, blood, and phlegm) led to emotional problems.