What are etiologic factors of mental illness?


What are Etiologic factors of mental illness? 
There is no identified single definite cause for mental illness. Mental illnesses are caused by one or more of the following factors.
  1. Genetic factors: abnormalities in chromosomes can cause mental illness. Children from mentally ill parents are more likely to develop mental illnesses than children of healthy parents.
  2. Following organic illnesses: Disease of cerebrovascular system, nervous system, endocrine system and illnesses such as epilepsy are associated with mental illnesses. 
  3. Social and environmental problems: poverty, tension, emotional stress, occupational and financial difficulties, unhappy marriage, broken homes, abuse and neglect, population mobility, changes in life due to natural disasters like earthquakes, flood and epidemics are associated.
  4. Psychological factors: early age experiences of abuse and other psychological trauma during childhood play an important role in the development of mental illness as an adult.
  5. Behavioral factors: indulging in drugs, alcohol and substances are associated with mental illness.
  6. Nutritional deficiency 
  7. Infections before and after delivery and birth trauma; 
  8. Accidents which cause head injury:
  9. Drug and Radiation accidents in early period of neural development in the womb.
Interplay between one or more of the above factors can lead to mental illnesses.