An evaluation of measurement invariance of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition borderline personality disorder criteria across heterosexual, lesbian, gay, and bisexual adults.

There is a robust, yet poorly understood relationship between nonheterosexual orientation and borderline personality disorder (BPD), with lesbian, gay, and bisexual individuals evidencing greater BPD symptoms compared to heterosexual individuals. Recent evidence suggests possible psychometric bias in BPD diagnostic criteria leading to greater endorsement among sexual minority individuals, which hinders researchers' ability to make valid group comparisons. The present study utilized an epidemiological sample of 35,995 men and women to evaluate the extent of differential item functioning (DIF) among BPD criteria across sexual orientation groups using a multiple indicators multiple causes approach. All criteria except affective instability and emptiness indicated DIF for at least one sexual minority focal group, although both demonstrated DIF in sensitivity analyses. DIF was most consistently indicated for suicidality, efforts to avoid abandonment, and impulsivity. Contrary to predictions, DIF was mostly nonuniform with greater item discrimination for sexual minority groups compared to their heterosexual counterparts. Finally, all estimated effect sizes were small, suggesting that DIF was not practically meaningful and unlikely to impact the validity of group comparisons for BPD criteria across heterosexual and nonheterosexual men and women. (PsycInfo Database Record (c) 2024 APA, all rights reserved).