The condition of borderline personality disorder (BPD) is one of the most distinctive psychiatric syndromes of adulthood. Environmental factors such as child sexual abuse, and other family influences such as maternal over involvement and inconsistency may have a role in its pathogenesis. Indeed, various forms of maternal psychopathology may be associated with patterns of mother–infant interaction that have an impact on infant development. In this podcast, Dr Margaret Murphy speaks with Professor Peter Hobson about his study which aimed to assess how women with BPD engage with their 12-18 month-old infants in separation-reunion episodes.