Nobody knows exactly how many people experience mental illness in Hong Kong, but as this former British colony undertakes its first-ever survey of mental health, it's widely believed that rates will match every other developed, industrialised country.

And when that data comes in, as Claudia Hammond reports in a special All In The Mind from Hong Kong, the gaps in mental health care will be exposed.

For years, the reality of mental illness in Hong Kong has remained hidden: a combination of shame, stigma and denial. Claudia hears from those who have experienced mental distress about the discrimination they suffer, and talks to mental health campaigners and professionals about the urgent need to expand and modernise the service to meet the soaring demand for mental health care.

Producer: Fiona Hill.