People in the past were locked up and filed away. Insane asylums were everywhere. Getting sent away - even for 'melancholy' was common. Fortunately most of these facilities have been shut down.

History is full of examples of those with mental illness - take the witches of Salem as an example. Take the Spanish Inquisition as and example.

Don't forget too that people didn't live as long to begin with.

Fast forward to today. Many people go undiagnosed. They live difficult unstable and turbulent lives. How many people have you encountered are considered 'high strung' or 'excentric'? My own mother was undiagnosed bipolar. I recall her living with a great deal of depression. I also recall being scared of her instability and when she would become 'difficult'.

I don't believe the numbers of MI are increasing, rather medicine is recognizing them and more diagnoses are happening.