Prevalence of multimorbidity in individuals with symptoms of substance use disorders and its association to physical activity and sedentary time

Multimorbidity is common among individuals with mental disorders, and substance use disorders, often considered secondary, may contribute to its development and complexity. Physical activity, increasingly recognized as a therapeutic tool for substance use disorders, could also contribute to the management of multimorbidity. Our objectives were to (1) compare the prevalence of multimorbidity between individuals with and without symptoms of substance use disorders within a cohort of people with mental disorders, (2) compare their physical activity and sedentary time, and (3) examine whether multimorbidity is associated with symptoms of substance use disorders, physical activity, and sedentary time. We did a cross-sectional study using the SIMPAQ international database including 1010 participants with mental disorders. For the analysis, prevalence ratios, ANOVA, and two sets of regression models were performed. We found that the prevalence of multimorbidity in individuals with symptoms of substance use disorders was 57.98% ( n = 495) and they appear to be slightly more active than people with no symptoms (2.57 ± 1.92; vs. 2.33 ± 1.87 h/week; p = 0.04). We also found that higher rates of multimorbidity was associated with lower sedentary time (OR = 0.92, p < 0.001), and symptoms of substance use disorders were associated with higher odds of physical multimorbidity (OR = 1.41, p = 0.05). These findings underscore the burden of multimorbidity among individuals with substance use disorders, and point to a complex relationship between sedentary time and multimorbidity, which warrants further investigation.