CAUSES
Doctors don’t know the exact cause of most mental illnesses. A combination of things, including your genes, biology, and your life experiences, seem to be involved.
Many mental illnesses run in families. But that doesn’t mean you will have one if your mother or father did.
Some conditions involve circuits in your brain that are used in thinking, mood, and behavior. For instance, you may have too much, or not enough, activity of certain brain chemicals called “neurotransmitters” within those circuits. Brain injuries are also linked to some mental conditions
Severe emotional, physical, or sexual abuse
A major loss, such as the death of a parent, early in life
Neglect
Major sources of stress, such as a death or divorce, problems in family relationships, job loss, school, and substance abuse, can trigger or aggravate some mental disorders in some people. But not everyone who goes through those things develops a mental illness.
It’s normal to have some grief, anger, and other emotions when you have a major setback in life. A mental illness is different from that.