Genetic brain disorders: The causes of mental disorders are complex, and interact and vary according to the particular disorder and individual. Genetics, early development, drugs, disease or injury, neurocognitive and psychological mechanisms, and life experiences, society and culture can all contribute to the development or progression of different mental disorders. ...

Genetic brain disorders: The causes of mental disorders are complex, and interact and vary according to the particular disorder and individual. Genetics, early development, drugs, disease or injury, neurocognitive and psychological mechanisms, and life experiences, society and culture can all contribute to the development or progression of different mental disorders.

Genetics could influence as: Family-linkage and twin studies have indicated that genetic factors often play an important role in the development of mental disorders. The reliable identification of specific genetic susceptibility to particular disorders, through linkage or association studies, has proven difficult.This has been reported to be likely due to the complexity of interactions between genes, environmental events, and early development or to the need for new research strategies.

The heritability of behavioral traits associated with mental disorder may be greater in permissive than in restrictive environments, and susceptability genes probably work through both "within-the-skin" (physiological) pathways and "outside-the-skin" (behavioral and social) pathways. Investigations increasingly focus on links between genes and endophenotypes - more specific traits (including neurophysiological, biochemical, endocrinological, neuroanatomical, cognitive, or neuropsychological) - rather than disease categories.