This work aims to review ADHD’s definition, epidemiology, frequent psychiatric comorbidities, differential diagnosis – highlighting it’s similarities with BPD –, treatment, and outcome.

A review of relevant literature was conducted alongside online database research (PubMed and Medscape).

ADHD is a neurodevelopmental disorder defined by persistent impairing levels of inattention, motor hyperactivity and impulsivity that exhibit a negative impact in functioning. It is estimated to affect 5% of children and 2.5% of adults. As the affected individual grows it is likely that the symptoms of hyperactivity will decrease, but the inattention, poor planning, and impulsivity tend to persist into adulthood, compromising social, academic, and occupational functioning.

It may be difficult to distinguish between ADHD and personality disorders, especially BPD. However, BPD has characteristic features like fear of abandonment, self-injury/suicidal behavior, extreme ambivalence, feelings of emptiness, and stress-related paranoia/severe dissociation, that are not present in ADHD.

Despite some similarities in clinical presentation in adolescents and young adults, PHDA and BPD differ substantially in their treatment, impairment in functioning, and outcome, making it crucial to establish a correct diagnosis which will enable proper treatment.