Incidence and predictors of mental ill-health in adults with intellectual disabilities: prospective study

Abstract

Background: The point prevalence of mental ill-health among adults with intellectual disabilities is 40.9%, but its incidence is unknown.

Aims: To determine the incidence and possible predictors of mental ill-health.

Method: Prospective cohort study to measure mental ill-health in adults with mild to profound intellectual disabilities.

Results: Cohort retention was 70% (n=651). The 2-year incidence of mental ill-health was 16.3% (12.6% excluding problem behaviours, and 4.6% for problem behaviours) and the standardised incidence ratio was 1.87 (95% CI1.51-2.28). Factors related to incident mental ill-health have some similarities with those in the general population, but also important differences. Type of accommodation and support, previous mental ill-health, urinary incontinence, not having impaired mobility, more severe intellectual disabilities, adult abuse, parental divorce in childhood and preceding life events predicted incident ill-health; however, deprivation, other childhood abuse or adversity, daytime occupation, and marital and smoking status did not.

Conclusions: This is a first step towards intervention trials, and identifying subpopulations for more proactive measures. Public health strategy and policy that is appropriate for this population should be developed.