Reviews an explanatory model that proposes the central role of impulsivity in suicide & suicidal behaviors. The term “impulsivity” describes a lack of ability to inhibit one’s actions. This disinhibition may result from disruption of the brain’s inhibitory mechanisms, from a lowering of psychological defences against suicide, or from a set of (sub) societal norms permissive of suicide. Borderline personality disorder (BPD) may be the ideal patient population for studying this association.