Prevalence of Psychotropic Medication Use and Association with Challenging Behaviour in Adults with an Intellectual Disability. A Total Population Study

Background: There is a high prevalence of psychotropic medication use in adults with Intellectual Disabilities (ID), often in the absence of psychiatric disorder, also associated with challenging behaviour. Previous research has focused on specific sample frames or data from primary care providers. There is also a lack of consistency in the definition of challenging behaviour used.

Methods: We adopted a total population sampling method. Medication data on 265 adults with ID were classified according to the Anatomical Therapeutic Chemical classification system. The Behaviour Problems Inventory - short form classified challenging behaviours. We examined the association between challenging behaviour and the use of psychotropic medication, and whether any association would still be present after accounting for socio-demographic and clinical characteristics.

Results: 70.57% of adults with ID were prescribed at least one class of any medication (mean per person =2.62; range 0-14). Psychotropic medications were used by 37.73% of participants with antipsychotics the commonest type used by 21.89% of individuals. Polypharmacy and high dosages were common. Generalised Linear Models indicated significant associations between psychotropic medication and the presence of a psychiatric diagnosis, challenging behaviour, older age and type of residence. Male gender was additionally associated with antipsychotic medication.

Conclusions: The use of a total population sample identified via multiple routes is less likely to overestimate prevalence rates of medication use. Current challenging behaviour was a predictor of medication use after controlling for other variables. Data indicate that there may be differences in prescribing patterns associated with different topographies of challenging behaviours.