The impact of borderline personality traits on challenging behaviour: implications for learning disabilities services

This case study describes how threats to stab people, in a client with learning disabilities, may have been inadvertently reinforced during detention in a medium secure unit by over‐looking borderline personality traits. Formulating the case from the biopsychosocial model of borderline personality disorder (Linehan, 1993), the article illustrates how an invalidating environment provided by learning disability services may have interacted with underlying difficulties in emotion regulation to reinforce challenging behaviour. Explaining threats to stab purely in terms of learning disability accidentally invalidated the client's emotional distress, so the only way he could convey how he was feeling was by escalating challenging behaviour. Risk management procedures also strengthened the client's belief that he was a dangerous person, and reinforced the challenging behaviour by gaining interpersonal attention. The need for learning disability services to be aware of how personality features contribute to learning disability presentations and to formulate from an interactive perspective is highlighted.