Cluster B Personality Disorders: Age & Sex Differences in Psychotropic Medication Use

Carlotta LUNGHI1,2,4, Lionel CAILHOL3, Victoria MASSAMBA4, Caroline SIROIS4, Elham RAHME7, Alain LESAGE3,4

1Department of Medical and Surgical Sciences, Université de Bologne, Bologne, Italy
2Population Health and Optimal Health Practices Axe; CHU de Québec-Université Laval Research Center, Québec, Canada
3Department of Psychiatry and Research Center, Institut Universitaire de Santé Mentale de Montréal, Montreal, Canada
4Institut National de Santé Publique du Québec,, Québec, Canada
5Department of Medicine, Division of Clinical Epidemiology, McGill University, Montreal, Canada
6Faculty of Pharmacy, Université Laval, Québec, Canada
7Department of Psychiatry and Addiction, Université de Montréal, Montreal, Canada

Introduction: Psychotropic medications are commonly prescribed to patients with Cluster B personality disorders (PDs). However, sex- and age-specific patterns of medication use remain inadequately explored. This study aims to fill this gap by analyzing sex and age differences in psychotropic medication use in the year before and after the initial diagnosis of cluster B PD, alongside trends spanning recent decades.



Methods: We used the Quebec Integrated Chronic Disease Surveillance System database to identify individuals (≥14 years) newly diagnosed with Cluster B PDs between 2002 and 2018 covered by the provincial public drug plan. Yearly and monthly proportions of users of psychotropic medications pre and post-diagnosis were measured, focusing on antipsychotics, antidepressants, anxiolytics, mood stabilizers, and ADHD medications. Data were stratified by sex and age groups. Robust Poisson regression models were employed to investigate the association between sex and the likelihood of exposure to various psychiatric medication classes after the first cluster B PD diagnosis.



Results: The study included 87,778 new cases of cluster B PDs, with an average age of 44.5 years; 57.5% were female. Psychotropic medication use increased post-diagnosis compared to pre-diagnosis: antidepressants (from 51.6% the year before diagnosis to 54.7% the year after), antipsychotics (35.9% to 45.2%), mood stabilizers (14.8% to 17.0%), and ADHD medications (5.1% to 5.9%). This increased use was similar across both sexes. Women were more likely to use antidepressants and anxiolytics, whereas men predominantly used antipsychotics and ADHD medications. Younger patients tended to use ADHD medications, and older ones anxiolytics. Over the study period, there was a noticeable increase in ADHD medication use, while anxiolytic use showed a declining trend.



Discussion-Conclusion: Cluster B PD patients showed high psychotropic medication use with distinct patterns based on age and sex. Prescription trends remained consistent across sexes but shifted in the last decades, reflecting evolving clinical practices