incidence of mental health problems over time?
* some like schizophrenia have stayed stable over time, while others increase or decrease
* classified into ICD (International Classification of Diseases) and DSM (Diagnostic and Statistical Manual for mental disorders)
* Mental Health Act 1959 reduced a lot of stigma surrounding mental disorders
* recent surveys show society as more tolerant and less judgemental nowadays, thanks to charities, campaigns and raised awareness