What causes mental illness?

It’s not easy to tell what causes mental illness. Research seems to show that a combination of biological and environmental factors lead to mental health problems. Biological factors like genetics, chemical imbalances, and damage to the central nervous system, such as a head injury, can play a role. Many environmental factors also can affect mental health, such as exposure to violence, break-up of a relationship, a traumatic event like a natural disaster or car crash, extreme stress, or the loss of a loved one.

Last revised: January 12, 2009