(107) Medication Use in The Year Before and After a Diagnosis of Cluster B Personality Disorder: Trends and Patterns Between 2002 and 2018 in Quebec, Canada

Publication Number: 781

Background: Cluster B personality disorders (PDs) are heterogeneous and severe mental disorders associated with excess mortality, especially in the presence of psychiatric comorbidities. Psychotherapy being the first-line treatment, the effectiveness of pharmacotherapy is not established beyond symptomatic relief. Little evidence exists on the real-world utilization of psychiatric medications among PD patients.

Objectives: To provide public managed care system linked health administrative databases evidence of the use of psychiatric medication classes in the one year before and after a diagnosis of cluster B PD and identify trends.

Methods: We conducted a population-based observational study using the Quebec Integrated Chronic Disease Surveillance System (QICDSS). Between 2002 and 2018, we identified Quebec residents (>=14 years) insured with the provincial drug plan with a first diagnosis of cluster B PD recorded in the QICDSS (since 1996). We retrieved all the claims for main psychiatric drug classes (antidepressants, anxiolytics, antipsychotics, mood stabilizers, and attention deficit hyperactivity disorders [ADHD] medications) in the year before and after PD diagnosis. We calculated the proportion of individuals exposed to the different medication classes and, for each class, the mean number and mean days’ supply of medications used. Results were presented according to the year of PD diagnosis to investigate prescription trends and by sex.

Results: Between 2002 and 2018, we identified 87,778 new cases of cluster B PD patients, with a mean age of 44.8 years (standard deviation: 19.5) and 57.5% women. The most prevalent psychiatric comorbidities were depression (50.9%), anxiety (49.7%), and psychotic disorders (37.5%). Most patients (71.0%) received at least one psychiatric medication in the year before PD diagnosis, and 78.5% received these drugs in the subsequent year. Similarly, the proportion of users increased for antidepressants (51.6-54.7%), antipsychotics (35.9%-45.2%), mood stabilizers (14.8%-17.0%), and ADHD medications (5.1%-5.9%), and remained relatively stable for anxiolytics (41.4%-41.7%). Trends showed increased use of antipsychotics and ADHD medications during the study period, while anxiolytics and mood stabilizers decreased, and antidepressants remained stable. Women used psychiatric medications more frequently, with differences according to drug classes.

Conclusions: Psychiatric medication use is highly prevalent among cluster B PD patients, even in the absence of evidence-based indications. There is an increase in antipsychotics, antidepressants, mood stabilizers and ADHD medications utilization in the year after a formal diagnosis is made, especially in more recent years.