Patterns of physiological arousal as well as self-reported emotional arousal associated with parasuicidal behavior in borderline personality disorder are examined. Women with BPD will participate in personally relevant imagery procedures while both physiological measures of arousal (heart rate, skin conductance, respiration, and blood pressure) as well as self-report measures are conducted. Arousal patterns associated with imagery involving suicide attempts and non-suicidal self-injury will be compared to each other and to arousal patterns elicited during control scenes using a four-stage methodology (cue situation, approach, incident, consequence). The research is based on the theory that parasuicidal behavior is learned via escape conditioning with relief from negative emotional states serving as the negative reinforcer. It is hypothesized that both non-suicidal self-injurious behaviors as well as non-lethal suicide attempts are maintained (i.e., negatively reinforced) by immediate reductions in aversive tension and emotional arousal, which will appear in both physiological and psychological measures. It is further hypothesized that changes in these patterns will predict subsequent changes in the frequency of parasuicide and suicide ideation four months after testing. Analysis of variance techniques and regression analyses are employed. Research of this nature is extremely important to help develop and improve treatments for chronic parasuicide in BPD. It remains a serious public health problem with few efficacious treatments, and is very costly in terms of health services utilization.