Low levels of household income are associated with several lifetime mental disorders and suicide attempts, and a decrease in income is associated with a higher risk for anxiety, substance use, and mood disorders, according to a report in the April issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

"To date, findings on the relationship between income and mental illness have been mixed," the authors write as background information in the article. "Some studies have found that lower income is associated with mental illness, while other studies have not found this relationship."

Jitender Sareen, M.D., FRCPC, of the University of Manitoba, Winnipeg, Canada, and colleagues analyzed data from the U.S. National Epidemiologic Survey of Alcohol and Related Conditions - the largest longitudinal, population-based mental health survey - to examine the relationship between income, mental disorders, and suicide attempts. A total of 34,653 non-institutionalized U.S. adults, age 20 years and older, were interviewed twice, three years apart.

"Participants with household income of less than $20,000 per year were at increased risk of incident mood disorders during the three-year follow-up period in comparison with those with income of $70,000 or more per year," the authors report.

"A decrease in household income during the two time points was also associated with an increased risk of incident mood, anxiety, or substance use disorders in comparison with respondents with no change in income," they write.

An increase in income during the follow-up period was not associated with any increase or decrease in the risk of developing mental disorders.

The authors believe their study findings have important public health implications.

"Most important, the findings suggest that income below $20,000 per year is associated with substantial psychopathologic characteristics and that there is a need for targeted interventions to treat and prevent mental illness in this low-income sector of the population," they conclude. "The findings also suggest that adults with reduction in income are at increased risk of mood and substance use disorders."

Arch Gen Psychiatry. 2011;68[4]:419-427.