How does our history and culture affect our understanding of psychological disorders?
In some cultures people think that schizophrenia is the devil possessing the person so exorcisms have been performed and people have been killed.
In other cultures mental health disorders are not reconsidered as a medical problem so are not acknowledged and the person is simply seen to be a liar/weirdo and told to get on with life.
In Western culture mental health is widely reconsidered and some think that we label people too freely. The book of dignosable mental health disorders start at 12 and now has over 200 different disorders in it.
To answer the question directly history helps shape our culture. Many "bad" people from the past e.g. Harold Shipman have been thought to have mental health disorders e.g. APD (Anti-social Personality disorder) and so have contributed to the diagnosis of "new" mental health disorders.