Purpose: Little is known regarding the links between mental disorder and lost income in low- and middle-income countries. The purpose of this study was to investigate the association between mental disorder and lost income in the first nationally representative psychiatric epidemiology survey in South Africa.
Methods: A probability sample of South African adults was administered the World Health Organization Composite International Diagnostic Interview schedule to assess the presence of mental disorders as defined in the Diagnostic and Statistical Manual of Mental Disorders, version IV.
Results: The presence of severe depression or anxiety disorders was associated with a significant reduction in earnings in the previous 12 months among both employed and unemployed South African adults (p = 0.0043). In simulations of costs to individuals, the mean estimated lost income associated with severe depression and anxiety disorders was $4,798 per adult per year, after adjustment for age, gender, substance abuse, education, marital status, and household size. Projections of total annual cost to South Africans living with these disorders in lost earnings, extrapolated from the sample, were $3.6 billion. These data indicate either that mental illness has a major economic impact, through the effect of disability and stigma on earnings, or that people in lower income groups are at increased risk of mental illness. The indirect costs of severe depression and anxiety disorders stand in stark contrast with the direct costs of treatment in South Africa, as illustrated by annual government spending on mental health services, amounting to an estimated $59 million for adults.
Conclusions: The findings of this study support the economic argument for investing in mental health care as a means of mitigating indirect costs of mental illness.