There’s a definite association between income and psychological well-being. That’s the conclusion of a study published online April 6 in The Journal of Clinical Psychiatry, which found that the lower a person’s income was, the more likely he or she was to report suicidal thoughts, suicide attempts, symptoms of psychological distress and excessive use of substances.

A body of research is devoted to teasing out the link between a person’s economic status and his or her likelihood of having a psychological disorder. In an effort to add further light on the subject, Katherine McMillan, BA, from the University of Regina in Saskatchewan, Canada, and her colleagues analyzed the results of three large surveys of American adults conducted between 2001 and 2003. The survey participants were randomly selected and matched the overall U.S. population in terms of demographics and other measures.

McMillan’s team found a significant link between low household income and certain psychological problems. People with the lowest income reported significantly more symptoms of psychological distress, as measured by the Kessler Psychological Distress Scale. Moreover, people with the lowest incomes were 74 percent more likely to report symptoms of excessive substance use, 77 percent more likely to report thoughts of suicide, and more than twice as likely to have committed suicide. White survey participants were more likely than other racial groups to report suicidal ideation, which entails thoughts of suicide.

The study doesn’t prove that low income causes psychological disorders—in fact, a number of studies show that psychological disorders reduce a person’s earning potential. Nevertheless, the authors conclude that “the strength of associations between income, suicidal ideation, suicide attempts and substance abuse points to the need for secondary prevention strategies among low-income, high-risk populations.”