Mental health
400 million people are mentally ill
78 countries have no mental health policy
340 million people suffer from depression
A report released on Saturday, to coincide with World Mental Health Day, showed that many countries have no mental health policy at all.
A World Health Organisation (WHO) survey carried out among its 191 member countries said mental health provision was severely under-resourced because of stigma, apathy and neglect.
Future problems
The head of the WHO, Dr Gro Harlem Brundtland, said these countries were storing up problems for the future.
"If we don't deal with mental illnesses, there is a burden not only on the mentally ill, on their families, their communities, there is an economic burden if we don't take care of people who need our care and treatment."
Many countries have inadequate community care facilities and lack primary health care treatment for severe mental disorders, such as schizophrenia or compulsive behaviour.
The problem is particularly bad in Africa and South East Asia, the WHO said.
Specific problems include a shortage of drugs to treat illnesses such as epilepsy, and a widespread failure to reintegrate people being treated for mental illness back into society.
The report recommends that governments make funding treatment a priority and encouraged patients to live in the community rather than locking them away in mental hospitals.
The Indian case
Among the events marking World Mental Health Day was a parade through the Indian capital, Delhi.
Campaigners described the neglect of people with psychiatric disability in the country as a national emergency.
The head of India's Institute of Human Behaviour and Allied Sciences said women faced the greatest problems, including being abandoned by their families following psychiatric illness.
He said that in his own institute, there were people who had been cured up to 20 years ago, but had nowhere to go.
Many of the issues surrounding mental illness in India are common to the developing world.
But the BBC's South Asia correspondent Mike Wooldridge says problems in India can be particularly acute because of its ever-growing population and limited public resources.
Nearly 25 million people in India are in need of mental health services.
Of these at least a third need help to cope with disability resulting from various psychiatric disorders.
Some experts have calculated that mental health problems contribute to an even greater reduction in the quality of life in India than tuberculosis or cancer.