Mental illness can often lead to a reduction in people's income. A U.S. survey of 4,982 people found that a serious mental illness in the previous 12 months significantly predicted reduced earnings. People with serious mental illness had 12-month earnings on average $16,306 less than other people. If replicated across the whole country this would cost $193.2 billion.
Kessler, Ronald C. ... [et al] - Individual and societal effects of mental disorders on earnings in the United States: results from the National Comorbidity Survey Replication American Journal of Psychiatry June 2008, 165(6), 703-711