About Mental Illness
Mental disorders that involve psychosis (being out of touch with reality, or totally involved in a reality that is entirely your own) are very disabling. In the words of The Global Burden of Disease, a study by the Harvard School of Public Health on behalf of the World Health Organization and the World Bank:
The burdens of mental illnesses, such as depression, alcohol dependence and schizophrenia, have been seriously underestimated by traditional approaches that take account only of deaths and not disability. While psychiatric conditions are responsible for little more than one per cent of deaths, they account for almost 11 per cent of disease burden worldwide.
Most significantly, the study shows that the burden of psychiatric conditions has been heavily underestimated. Of the ten leading causes of disability worldwide in 1990, measured in years lived with a disability, five were psychiatric conditions: unipolar depression, alcohol use, bipolar affective disorder (manic depression), schizophrenia and obsessive compulsive disorder... Altogether, psychiatric and neurological conditions accounted for 28 per cent of all YLDs (years lived with disability) compared with 1.4 percent of all deaths and 1.1 percent of years of life lost. The predominance of these conditions is by no means restricted to the rich countries, although their burden is highest in the Established Market Economies...