Abstract
BACKGROUND: It is essential to understand the complex interaction among mental illness, challenging behaviour and psychotropic medication prescribing among adults with intellectual disabilities to help reduce overmedication of psychotropics. METHODS: We analysed data from the Institute of Health Information and Statistics of the Czech Republic to estimate the prevalence of mental illness, challenging behaviour and psychotropic prescribing between 2010 and 2022 and incidence between 2015 and 2022. RESULTS: 62,636 (54% males) adults with intellectual disabilities contributed 704,503 person-years of data. In 2010, the prevalence of concomitant mental illness (ICD-10, F20-48) was 15·7%, challenging behaviour 29% and any psychotropic prescription 55%, increasing in 2022 to 17·3%, 30·5% and 59%, respectively. The prevalence of most individual mental illness categories either remained the same or marginally increased between 2010 and 2022, except anxiety disorders, the neurodevelopmental disorders like autism and attention-deficit hyperactivity disorder (ADHD), which showed a significant increase. The incidence of new diagnoses of mental illnesses and challenging behaviour decreased between 2015 and 2022, except for the neurodevelopmental disorders, which increased significantly. The incidence of challenging behaviour correlated significantly with psychoses, bipolar disorder, and anxiety disorder. The overall prevalence of most psychotropic prescribing correlated significantly with the prevalence of mental illnesses and challenging behaviour. Among those receiving antipsychotics, only 18% in 2010 and 19% in 2022 had severe mental illness (psychoses and/or bipolar disorder), which are the licensed indications for long-term antipsychotic prescriptions. In 2010, among those with challenging behaviour, 82% received psychotropics, 62% antipsychotics, 20% antidepressants, 17% anxiolytics, 30% mood stabilisers, and 0·4% hypnotics and sedatives. The incidence rates of new prescriptions among participants who displayed challenging behaviour fell for any psychotropics, antipsychotics, antidepressants and anxiolytics. However, the incidence of new prescriptions increased for mood stabilisers, and significantly for hypnotics/sedatives (Incidence Rate Ratio: 0.61; 95% Confidence Interval: 0.45–0.81; p < 0.001). CONCLUSIONS: Challenging behaviour was significantly associated with some mental illnesses. Both mental illness and challenging behaviour were significantly associated with psychotropic medication prescribing. The prevalence of psychotropic medication prescribing overall and especially among those displaying challenging behaviour was high and showed a significant increase in antidepressants and hypnotics/sedatives prescriptions over 12 years. CLINICAL TRIAL NUMBER: Not applicable.