Psychotropic drug use in people with intellectual disability: patterns of use and critical evaluation: patterns of use and critical evaluation

Treatment with psychotropic drugs is highly prevalent in people with intellectual disability, especially in those with behavioural problems. The high rates of psychotropic drug use in this population is contrasted by the limited evidence on their effectiveness and the high risk of adverse events. The overall objective of this thesis was to critically evaluate psychotropic drug use in people with mild to borderline intellectual disability and behavioural problems. This thesis showed that people with intellectual disability are underrepresented in randomised controlled trials (RCTs) of pharmacological treatment of behavioural problems. At the same time psychotropic drugs are used extensively, often for long periods of time and without a clear indication for use. Psychotropic drug use often starts young, with 30% of institutionalised children and adolescents with intellectual disability and behavioural problems being treated with at least one psychotropic drug. Adverse drug events are common in treatment with psychotropic drugs, but are often not diagnosed in people with intellectual disability. Adverse events, such as serious movement disorders are very common, 44% of in-patient adults with mild to borderline intellectual disability and behavioural problems had a movement disorder. To improve the quality of pharmacotherapy a medication review intervention was performed in which the medication used by people with intellectual disability was thoroughly reviewed by a team consisting of the psychiatrist, a pharmacist and a nurse. In over a third of all medications used a drug-related problem was found, that needed intervention. In almost 60% of those cases the recommended actions were also executed.

The research in this thesis has increased the knowledge on psychotropic drug use in people with mild to borderline intellectual disability and behavioural problems. The findings from this thesis show that psychotropic drugs play a major role in treatment of people with intellectual disability and behavioural problems, even though the evidence base is weak. People with intellectual disability and behavioural problems are at risk of starting psychotropic drugs at a young age and for unclear indications. The adverse events associated with psychotropic drug use can have a negative impact on the quality of life. To improve care for people with intellectual disability more attention is needed for pharmaceutical care during regular treatment plan evaluations, in combination with periodic structured medication reviews for complicated patients. Prescribing psychotropic drugs in people with intellectual disability and behavioural problems is complicated. The 6-step model of the World Health Organization (WHO) Guide to Good Prescribing can provide tools in the process of prescribing a (psychotropic) drug in people with intellectual disability. We propose the medication review as an additional step (6A) in the 6-step model. In the process of decision-making to start, continue or discontinue (psychotropic) drugs, a multidisciplinary approach is essential.