Nearly 10 million Americans experience a serious mental illness within any one year, and 24/7 Wall St. outlines the 12 states that have the largest adult populations struggling with various forms of mental illness, including depression and bipolar disorder. To come up with this ranking, the site examined surveys administered between 2013 and 2014 by the Substance Abuse and Mental Health Services Administration. The reviewers also looked at per capita drug prescription rates, poverty rates, education, and mental health legislation, among other factors, to round out its analysis. Here, the six states dealing the most with this issue: