Challenges and pitfalls of antipsychotic prescribing in people with learning disability

INTRODUCTION
In this opinion piece we highlight the current concerns of prescribing antipsychotics to people with learning disability (PWLD) and propose a system of monitoring of antipsychotic prescribing in general practice that, we argue, will reduce inappropriate antipsychotic use.

Learning disability, synonymous with the term ‘intellectual disabilities’,1 affects about 1–2% of the general population2 and is characterised by significant impairments of both intellectual and adaptive functioning, and an onset before 18 years.3

PWLD have high rates of ‘challenging behaviour’ (CB) — for instance, acts of aggression towards people or property, self-neglect, and self-harm — and risk exploitation.2 CB is a social construct to enumerate a behavioural or mental pattern that may cause suffering or a poor ability to function in life. It is best understood based on learning theory and the principles of applied behavioural analysis. Mental illness is a structured diagnostic concept that encompasses a large range of recognised emotional and behavioural disorders and its diagnosis requires robust application of the diagnostic schedules. It is reasonable to state that most PWLD with mental illness have CB but the majority of PWLD with CB might not satisfy criteria for mental illness. Therefore, the therapeutic approach to CB can be very different from a diagnostic one. However, there is significant overlap between CB and the presence of mental illnesses, with the latter also being higher in PWLD than in the general population. Deficits in communication, atypical clinical presentations, and differences in diagnostic coding methods mean that mental illness can be under-recorded, particularly in those with severe degrees of learning disability.1,4 This means that the clinician needs to be aware not just of what is observed behaviourally, but also whether there is something underlying diagnostically. A formulation based on both these elements is central to deciding whether there is a need to prescribe medication.