Biologic theorists believe chromosomal or nervous system disorders are the cause. Social theorists believe learned behavior responses cause the disorders.
Psychodynamic theorists use deficiencies in ego development to explain the causes.
They lack sufficient coping mechanisms to be adaptive and deal with everyday stresses and problems. These disorders are manifested by difficulties in interpersonal relationships with others. The disorders are widespread, with no actual incidence available. There is no known way to prevent this disorder. Symptoms vary widely in individuals and differ with the diagnosis.