Psychotropic medication use for adults and older adults with intellectual disability; selective review, recommendations and future directions

Abstract

A growing expert consensus has emerged to guide prescribing behavior and monitoring of psychotropic medications in adults and older adults with intellectual disability (ID). However, there is little empirically-derived evidence to inform physician selection of specific categories of psychotropic medication for treatment of "challenging" behaviors in this vulnerable population (such as aggression to self, others and objects; self-injurious behaviors; repetitive stereotypic behaviors; and hyperactivity). Difficulties with application of formal definitional diagnostic criteria and reliable assignment of psychiatric diagnoses to adults with ID, which is often difficult due to their poor communication skills, contribute to confusion and uncertainty surrounding medication selection. Long-term administration of antipsychotic medications are commonly prescribed for challenging behaviors in spite of their questionable long-term efficacy, leading some to suggest that their "episodic" short-term administration for imminent dangerousness to self and others or when difficult-to-find residential placements are threatened is preferred to their long-term administration. Further, literature supports engagement of interdisciplinary treatment teams to seek causes for challenging behaviors, formulate non-pharmacological psychosocial and behavioral plans for their amelioration and, if medications are initiated, convene regular medication monitoring to identify "drug-related problems". Medication monitoring is important because medication-related adverse events cause or contribute to challenging behaviors, which can sometimes be improved by dose reduction, medication discontinuation and/or elimination of polypharmacy and co-pharmacy. Importantly, medications themselves may interfere with self-reported measures of Quality of Life. The data clearly highlight the need for well-designed randomized controlled clinical trials in samples that are homogeneous with respect to severity of ID and residential setting; moreover, they should include a wider variety of clinical and safety outcome measures. Preclinical studies have suggested novel pharmacological strategies to prevent progressive worsening of adaptive function in adults with Down syndrome in particular, and improvement of cognition in adults with ID in general, irrespective of the etiopathogenesis of the ID. Translational clinical trials to address pathogenic mechanisms of ID, as well as challenging behaviors, are anticipated but raise societal issues pertaining to protection of this vulnerable population enrolling in clinical trials and prioritization of urgent therapeutic targets (e.g., amelioration of challenging behaviors versus improving or preserving intellectual functioning).

Keywords: Adults; Adverse events; Challenging Behaviors; Intellectual disability; NMDA receptor; Psychotropic medications; α(7) nicotinic acetylcholine receptor.