Obsessive-compulsive symptoms and disorder in clozapine-treated schizophrenia

Jonathan Gerard Hsueh Ching Seow; Deborah Hui Yi Tan; Yuen Mei See; Jie Yin Yee; Boon Tat Ng; Charmaine Tang; Jimmy Lee

doi:10.1016/j.sjpmh.2023.10.001

Obsessive-compulsive symptoms and disorder in clozapine-treated schizophrenia

Span J Psychiatry Ment Health. 2023 Oct 31:S2950-2853(23)00054-6. doi: 10.1016/j.sjpmh.2023.10.001. Online ahead of print.

Authors

Jonathan Gerard Hsueh Ching Seow¹, Deborah Hui Yi Tan², Yuen Mei See³, Jie Yin Yee³, Boon Tat Ng⁴, Charmaine Tang⁵, Jimmy Lee⁶

Affiliations

¹ North Region, Institute of Mental Health, Singapore. Electronic address: jonathangerard.seow@mohh.com.sg.
² North Region, Institute of Mental Health, Singapore.
³ Research Division, Institute of Mental Health, Singapore.
⁴ Department of Pharmacy, Institute of Mental Health, Singapore.
⁵ Department of Psychosis, Institute of Mental Health, Singapore.
⁶ North Region, Institute of Mental Health, Singapore; Research Division, Institute of Mental Health, Singapore; Department of Psychosis, Institute of Mental Health, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.

PMID: 37918717
DOI: 10.1016/j.sjpmh.2023.10.001

Abstract

Background: Obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorder (OCD) are commonly reported in patients with schizophrenia. Furthermore, the use of clozapine in treatment-resistant schizophrenia has been thought to induce or aggravate these disorders. To date, there is a paucity of research regarding the prevalence and associated factors. Hence, this study aims to report the prevalence of OCS and OCD, and examine potential risk factors, in clozapine-treated schizophrenia.

Methods: This is a cross-sectional study conducted in the only tertiary hospital for psychiatric patients in Singapore. In total, 162 patients on a stable dose of clozapine were recruited for this study; 159 patients with a diagnosis of schizophrenia or schizoaffective disorder were included in the current analysis. Sociodemographic, clinical and treatment factors were analysed to identify factors associated with OCS and OCD.

Results: The prevalence of OCS and OCD is 21.4% and 12.6% respectively. Factors associated with OCS include younger age (OR:0.96, p=0.033) and younger age of onset of psychosis (OR:0.92, p=0.017). There were no significant factors associated with OCD. However, in an analysis of both OCS and/or OCD, factors associated include younger age (OR:0.96, p=0.027) and younger age of onset of psychosis (OR:0.91, p=0.016). Severity of psychotic illness and Clozapine dose were not associated with OCS or OCD in clozapine-treated schizophrenia.

Discussion & conclusions: Our results suggest a high prevalence of OCS and OCD in clozapine-treated schizophrenia which clinicians should routinely screen for. Further research is warranted to establish the link between the factors identified in this study and OCS/OCD in clozapine-treated schizophrenia.

Keywords: Clozapine; Compulsions; OCD; Obsessions; Obsessive–compulsive disorder; Obsessive–compulsive symptoms; Schizophrenia.