Clozapine for Patients With Intellectual Disabilities: A Case Series Illustrating the Clinical Potentials.

Background: Challenging behaviours (CBs) are common in patients with intellectual disabilities (IDs) and diagnosing an underlying primary psychiatric disorder is often difficult. Even though many respond to non-pharmacological or pharmacological interventions persistent aggressive and self-injurious behaviour occur and no treatment-resistant guideline exists. We aim to present clinical scenarios regarding patients with ID and persistent CB with or without a primary psychiatric disorder where clozapine could be considered. Case Presentation: We present five patients with ID with persistent CB with or without a primary psychiatric disorder treated with clozapine. Four of the five patients responded well to clozapine treatment with markedly decreased CB, and two patients had reduced psychotic- or affective symptoms. Side-effects were mild and manageable. Haematological monitoring was performed with a point-of-care (POC) test device. Conclusions: We show that clozapine can be efficacious in persistent CB and/or treatment-resistant psychiatric symptoms in patients with ID. Monitoring and managing side-effects were possible. Impact and Implications: We suggest that clozapine should be considered in patients with ID regardless of a primary psychiatric disorder when CB does not respond to non-pharmacological and first line pharmacological treatment. It is possible to monitor and manage side-effects with a systematic approach including the use of POC testing.