Mental disorder is characterized chiefly by abnormal behavior or an inability to function socially, including diseases of the mind and personality and certain diseases of the brain. It is also known as mental illness or mental disease.
There are many causes of mental disorders. Your genes and family history may play a role. Your life experiences, such as stress or a history of abuse, may also matter. Biological factors can also be part of the cause.
A traumatic brain injury can lead to a mental disorder. A mothers exposure to viruses or toxic chemicals while pregnant may play a part. Other factors may increase your risk, such as use of illegal drugs or having a serious medical condition like cancer.