What is often the cause of mental illness?

Question: What is often the cause of mental illness?
- Keywords:
  cause,
  mental illness
Asked by anon-192085 to Kelly on 5 Nov 2018.
- Kelly Rushton answered on 5 Nov 2018:
  
  There are lots of different causes of mental illness – sometimes it can be caused by our genetics, sometimes it can be caused by things that have happened to us in our lives, and often its a mixture of both.

Question: What is often the cause of mental illness?