Polypharmacy in the treatment of people diagnosed with borderline personality disorder: repeated cross-sectional study using New Zealand's national databases

BackgroundThere is insufficient evidence to support the pharmacological treatment of borderline personality disorder. However, previous out-patient cohorts have described high rates of polypharmacy in this group. So far, there have been no national studies that have considered polypharmacy in borderline personality disorder.AimsTo describe psychotropic polypharmacy in people with borderline personality disorder in New Zealand.MethodNew Zealand's national databases have been used to link psychotropic medication dispensing data and diagnostic data for borderline personality disorder. Annual dispensing data for 2014 and 2019 have been compared.ResultsFifty percent of people with borderline personality disorder who were dispensed medications had three or more psychotropic medications in 2014. This increased to 55.9% in 2019 (P < 0.001). Those on seven or more psychotropics increased from 8.4 to 10.7% (P < 0.023). Quetiapine was the most dispensed psychotropic medication, being given to 53.8% of people dispensed medication with borderline personality disorder in 2019. Lorazepam dispensing showed the largest increase, going from 15.5 to 26.7% between 2014 and 2019 (P < 0.001).ConclusionsThere is a large burden of psychotropic polypharmacy in people with borderline personality disorder. This is concerning because of the lack of evidence regarding the efficacy of these medications in this group.