An Open-Label Discontinuation Trial of Long-Term, Off-Label Antipsychotic Medication in People With Intellectual Disability: Determinants of Success and Failure

Abstract

Although physicians are aware of the risks of prescribing long-term off-label antipsychotics in people with intellectual disability, attempts to discontinue often fail. This study aimed to identify potential determinants of successful and failed discontinuation. Long-term off-label antipsychotics were tapered in 14 weeks, with 12.5% of baseline dose every 2 weeks. Participants living in facilities offered by intellectual disability service providers, ≥6 years, with an IQ <70 were eligible to discontinue antipsychotic use, as judged by their physicians. The primary outcome was achievement of complete discontinuation at 16 weeks; changes in the Aberrant Behavior Checklist (ABC) and its 5 subscales were secondary outcomes. Potential determinants of the success or failure in discontinuing antipsychotics were psychotropic drug use and participants' living circumstances, medical health conditions, and severity of behavioral symptoms and neurologic side effects. Of 499 eligible clients, 129 were recruited. Reasons for client non-participation were clinician concerns that discontinuation might increase challenging behaviors and changes in clients' environment. Of the 129 participants, 61% had completely discontinued antipsychotics at 16 weeks, 46% at 28 weeks, and 40% at 40 weeks. ABC total scores increased in 49% of participants with unsuccessful discontinuation at 16 weeks. Autism, higher dose of antipsychotic drug, higher ABC and akathisia scores, and more-frequent worsening of health during discontinuation were associated with a lower incidence of complete discontinuation. Thus, in a selected sample of participants whom responsible clinicians had deemed discontinuation of antipsychotics could be attempted, 40% had achieved and maintained discontinuation at end of follow-up. Physicians should try to address patients' conditions that may hamper discontinuation.

Keywords: antipsychotic drugs; determinants; discontinuation; intellectual disability; mental health; off-label use; psychopharmacology.