How can you serve the mental health needs of a country where there are just 10 psychiatrists for a population of 13 million people?

That is the challenge facing Zimbabwe, but will be familiar to many in low and middle income countries. Globally, more than one billion people live with a mental illness, but provision varies radically according to where you live.

Like most low and middle income countries, Zimbabwe puts people with mental health problems in hospitals, rather than treating them in the community, says Professor Dixon Chibanda of the University of Zimbabwe - one of the country's handful of trained psychiatrists.

"These institutions are not able to meet the needs of people with mental health problems - they are not user friendly and they fuel stigma because of their excessive use of medication and their excessive use of seclusion," he says.

"There is a strong belief that mental illness is something caused by spirits or demon possession," he adds.

"People are sent to traditional healers or witch doctors. That fuels the stigma. If you are labelled as having a demon when what you have is schizophrenia or epilepsy it's going to be very hard to get any proper treatment."