Background:
Psychiatric medications are often prescribed to patients with cluster B personality disorders (PDs). This study aimed to explore sex differences in the use of psychiatric medications in the 1-year before and after the first diagnosis of PD and to identify trends and patterns between 2002 and 2018.

Methods:
We used the Quebec Integrated Chronic Disease Surveillance System (QICDSS) to identify all Quebec residents (>=14 years) insured with the public drug plan and with a first diagnosis of a cluster B PD. We retrieved all the claims for psychiatric medication classes during the one year before and after the diagnosis and calculated yearly and monthly proportions of individuals exposed to psychiatric medications. We also tested age and sex-adjusted trends in medication use changes using robust Poisson regression models.

Results:
We identified 87,778 individuals with a first diagnosis of a cluster B PD. The mean age was 44.5 years (SD: 19.5), and 57.5% were women. Psychiatric comorbidities were common, with the most prevalent being depression (50.9%), anxiety (49.7%), and psychotic disorders (37.5%). The proportion of medication users increased after diagnosing a PD for both sexes. Women were more frequently exposed than men to at least one psychiatric medication (74.3%-80.5% vs 68,0%-71.0%). Among patients diagnosed in 2018-19, women were more likely to use antidepressants (60.6% vs 46.9%) and anxiolytics (33.2% vs 27.4%), while men were more likely to use antipsychotics (38.3% vs. 35.2%) and ADHD medications (11.2% vs 10.5%). Mood stabilizers had similar proportions (11.2% of women and 11.4% of men). Trends over the study period showed a marked increase in ADHD medications use, while anxiolytics use decreased.

Conclusions:
Differences in psychiatric medication use exist between men and women with cluster B PDs according to medication classes. Changes in prescriptions over the last decade are similar for men and women.