Bias in the diagnosis of borderline personality disorder among sexual and gender minority persons: Results from a vignette-based experiment

Sexual and gender minority (SGM) individuals are diagnosed with borderline personality disorder (BPD) more than cisgender heterosexuals. Using a large sample of mental health practitioners in the U.S. and Canada (N=426) we examined bias in the diagnosis of BPD. Mental health practitioners were randomly assigned to receive one of three clinical vignettes (cisgender heterosexual man, cisgender gay man, or transgender woman) and asked to provide psychiatric diagnoses based on the vignette. Mental health practitioners demonstrated a predilection to diagnose BPD when presented with the transgender (OR=1.99, p=.01), not the cisgender gay condition (OR=1.34, p=0.29), vignette when compared with those presented the cisgender heterosexual vignette. Psychiatrists, mental health counselors, and clinical social workers were significantly more inclined to diagnose BPD than psychologists, though reasons for underdiagnosis differed across groups. These findings bear important implications for future training given the nature of the mental health workforce in the U.S.