Epidemiology of mental health problems in adults with learning disability: an update

Epidemiological studies measuring prevalence rates and factors associated with mental health problems in adults with learning disability have produced very different and sometimes contradictory results, mainly because of methodological problems. Consequently, much of the epidemiology of mental health problems in this population is still unknown, although improved methodology and additional information are emerging. This article describes the methodological difficulties of studies, the reported prevalence rates in the context of these difficulties and what is currently known about the factors associated with mental health problems in this population.