Cumulative burden of comorbid mental disorders, substance use disorders, chronic medical conditions, and poverty on health among adults in the U.S.A.

The health of individuals in the U.S.A. is increasingly being defined by complexity and multimorbidity. We examined the patterns of co-occurrence of mental illness, substance abuse/dependence, and chronic medical conditions and the cumulative burden of these conditions and living in poverty on self-rated health. We conducted a secondary data analysis using publically-available data from the National Survey on Drug Use and Health (NSDUH), which is an annual nationally-representative survey. Pooled data from the 2010-2012 NSDUH surveys included 115,921 adults 18 years of age or older. The majority of adults (52.2%) had at least one type of condition (mental illness, substance abuse/dependence, or chronic medical conditions), with substantial overlap across the conditions. 1.2%, or 2.2 million people, reported all three conditions. Generally, as the number of conditions increased, the odds of reporting worse health also increased. The likelihood of reporting fair/poor health was greatest for people who reported AMI, chronic medical conditions, and poverty (AOR = 9.41; 95% CI: 7.53-11.76), followed by all three conditions and poverty (AOR = 9.32; 95% CI: 6.67-13.02). For each combination of conditions, the addition of poverty increased the likelihood of reporting fair/poor health. Traditional conceptualizations of multimorbidity should be expanded to take into account the complexities of co-occurrence between mental illnesses, chronic medical conditions, and socioeconomic factors.