Borderline Personality as a Factor in Late, Missed, and Mis-Diagnosis in Autistic Girls and Women: A Conceptual Analysis.

Autism without intellectual disability is diagnosed later and with greater difficulty in girls/women relative to boys/men. For autistic girls and women, the journey to an autism diagnosis may include one or more misdiagnoses. Misdiagnosis with borderline personality disorder (BPD) or borderline traits may be particularly common, and characteristics often observed in autistic girls and women may contribute specifically to a risk of misdiagnosis with BPD. This review draws from a burgeoning literature on autism in girls and women to provide a detailed discussion of differential diagnosis of BPD and autism in cisgender girls/women, with a focus on phenotypic traits and/or their presentation that may be more common in autistic girls/women and that may be particularly prone to miscategorization as BPD. Distinctions between autism and BPD are identified, emphasizing the need for scrutiny of an individual's clinical presentation to tease apart differences between the autism and BPD phenotypes. We highlight instances in which similar phenotypic expressions may be driven by differing underlying factors. Implications for the distinction of autism and BPD/borderline traits in informing appropriate therapeutic intervention are discussed.