Throughout history people have explained mental disorders in different kinds of ways. Ways that suit their culture and society.
In some societies people with mental disorders were regarded as being possessed by devils and were tortured to be drived out. While in others some people were treated fine and were thought to be divinely inspired. Artistic geniuses such as Vincent van Gogh.
People think there is a link between mental illness and creativity.

Throughout history however, in general the mentally ill were badly treated. For instance. in the 19th century large asylums were built for the metally ill, as places for safety. Yet these asylums had appalling treatment. They probaly made them even more "mental".

Not until recently have powerful drugs and new pyshcological theories, has the mentally ill been effectively treated.

There are many different types of Mental Disorders. Some might not have even been discovered yet.

Many factors come into the causes of a mental disorder. Some mental disorders can be heredity. Some mental disorders can be caused when the Mother is pregnant and is drinking or smoking. Or it could just be a gamble.

In todays society the metally ill are accepted as normal human beings.