Affective instability and suicidal ideation and behavior in patients with borderline personality disorder.

This study employed an Experience Sampling Methodology (ESM) to test whether various elements of affective instability can predict future suicide ideation in patients with borderline personality disorder (BPD) and a history of recurrent suicidal behavior. Eighty-two individuals with BPD and a history of recurrent suicidal behavior were followed prospectively for one month during which time they recorded their current mood states, 6 times daily over three weeks. Accounting for a set of robust suicide risk factors in multiple regression analyses, only negative mood intensity was significantly related to intensity of self-reported suicide ideation and to number of suicidal behaviors over the past year. Other elements of affective instability examined (e.g., mood amplitude, dyscontrol, and reactivity) were not associated with future suicide ideation or with recent suicidal behavior. Affective instability in patients with BPD is highly variable from one individual to another and is characterized by high levels of intense negative mood. These negative mood states, versus other aspects of mood variability, seem to be more closely tied to the occurrence of suicidal ideation and behavior.