Relationships between mixed features and borderline personality disorder in 2811 patients with major depressive...

The study focused on the relationship between mixed depression and borderline personality disorder (BPD).

The sample comprised 2811 patients with a major depressive episode (MDE). Clinical characteristics were compared in patients with (BPD+) and without (BPD-) comorbid BPD and in BPD+ with (MXS+) and without (MXS-) mixed features according to DSM-5 criteria.

A total of 187 patients (6.7%) met the criteria for BPD. A DSM-IV-TR diagnosis of bipolar disorder (BD) was significantly more frequent in patients with BPD+ than in patients with BPD. Patients with BPD+ were significantly younger and reported lower age at onset than BPD-. Patients with BPD+ also showed more hypomania/mania in first-degree relatives in comparison with patients with BPD-, as well as more psychiatric comorbidity, mixed features, atypical features, suicide attempts, prior mood episodes and antidepressant-induced hypo/manic switches. Mixed features according to DSM-5 criteria were observed in 52 (27.8%) BPD+. In comparison with MXS-, MXS+ were significantly younger at age of onset and at prior mood episode and had experienced more mood episodes and hypo/manic switches with antidepressant treatments.

Major depressive episode patients with comorbid BPD reported a high prevalence of mixed features and BD. The presence of DSM-5 mixed features in MDE patients with BPD may be associated with complex course and reduced treatment response.