Gender dysphoria and personality disorders: associations with proceeding to and discontinuing medical gender reassignment

Personality disorder (PD) diagnoses, especially borderline PD, are overrepresented among individuals seeking medical gender reassignment (GR), but their impact on progression to or discontinuation of GR is unclear. This may differ between adults and adolescents due to ongoing personality development in youth. This register-based follow-up study examined 3665 individuals referred to Finnish gender identity services between 1996 and 2019. Data on specialist-level psychiatric treatments from 1994 to 2022 were obtained from the National Care Register for Health Care. The study assessed associations between PD diagnoses (any, and specifically borderline PD) and outcomes related to medical GR, including treatment initiation and discontinuation. Analyses accounted for age group (adolescents vs. adults), transition direction, and non-PD psychiatric comorbidities. Subjects with a PD diagnosis were significantly less likely to initiate GR than were those without a PD (33% vs. 46.1%, p < .001). However, among those who began GR, presence of PD did not appear to increase the likelihood of discontinuation. These findings held equally for across both adolescents and adults. Similar results were found for borderline PD specifically. Personality disorders may be linked to challenges in forming a stable gender identity, potentially reducing the likelihood of initiating medical GR. However, once treatment begins, PD does not appear to increase the risk of discontinuation.