Ketamine/esketamine in the treatment of depression with comorbid borderline personality disorder or traits: A systematic review of effectiveness

Introduction: There is mounting evidence for the use of ketamine/esketamine in the treatment of depression. This paper examines how comorbid borderline personality disorder, or traits, may impact the efficacy of ketamine/esketamine in the treatment of depressive disorders. Aims: To evaluate the efficacy of ketamine/esketamine in the treatment of depression where there are comorbid borderline personality disorder/traits. Method: MEDLINE, Embase, APA PsycInfo, CINAHL and Scopus databases were searched for English language journal articles focusing on the use of ketamine/esketamine to treat depression in patients with comorbid borderline personality disorder/traits. Analysis included study design and intervention, efficacy statistics relating to the treatment of depression, as well as study limitations. Results: Nine studies ( n = 281) were included. Ultimately, patients with depression and comorbid borderline personality disorder/traits were equally likely to respond to ketamine/esketamine as those with depression but without borderline personality disorder/traits. Conclusion: This is the first systematic review to assess the effectiveness of ketamine/esketamine in this cohort. Our findings suggest that ketamine/esketamine may be useful in improving symptoms of depression, in those with comorbid borderline personality disorder. Limited study data are available; however, given case reports of suicidal ideation and self-harm following treatment cessation, as well as indications of a higher risk of acute dissociation in individuals with borderline personality disorder, clinicians should exercise caution when using ketamine to treat depression in this population. More data are required including a larger randomised control trial to assess the efficacy and side effects of ketamine/esketamine in this study population. Clinicians should, where available and appropriate, consider offering ketamine/esketamine to patients in this cohort.