The 5-year pre- and post-hospitalization treated prevalence of mental disorders and psychotropic medication use in critically ill patients: a Canadian population-based study

The interplay between critical illness and mental disorders is poorly understood. The purpose of this study is to measure both the treated prevalence of mental disorders and psychotropic medication use before and after hospitalization and the impact of intensive care unit (ICU) admission on these outcomes. Using a population-based administrative database in Manitoba, Canada, 49,439 ICU patients admitted between 2000 and 2012 were compared to two matched comparison groups (hospitalized; n = 146,968 and general population; n = 141,937). Treated prevalence of mental disorders and psychotropic medication prescriptions were measured in the 5-year periods before and after the hospitalization. Multivariable models compared adjusted prevalence ratios (APRs) between populations. The 5-year treated mental disorder prevalence in the ICU population increased from 41.5% pre-hospitalization to 55.6% post-hospitalization. Compared to non-ICU hospitalized patients, the adjusted treated mental disorder prevalence in ICU patients was lower prior to hospitalization (1-year APR 0.94, 95% CI 0.92–0.97, p < 0.0001; 5-year APR 0.99, 95% CI 0.98–1.00, p = 0.1), but higher following discharge (1-year APR 1.08, 95% CI 1.05–1.11, p < 0.0001, 5-year APR 1.03, 95% CI 1.01–1.05, p < 0.0001). A high proportion of ICU patients received antidepressant, anxiolytic and sedative-hypnotic prescriptions before and after their hospitalization. In multivariable analyses, ICU exposure was associated with an increase in mood, anxiety and psychotic disorders, and sedative-hypnotics use (p < 0.0001 for all Time × Group interactions). During the 5 years after admission to ICU, there is a significant increase in treated prevalence of mental disorders and psychotropic medication use compared to the 5 years prior to ICU and compared to general population and hospital cohorts. Prevention and intervention programs that identify and treat mental disorders among survivors of critical illness warrant further study.