Comparison of affective instability in borderline personality disorder and bipolar disorder using a self-report measure.
BACKGROUND
This study used a new self-report instrument to measure frequency and intensity of nine dimensions of affective instability, as well as the extent to which affective instability was interpersonal, in subjects endorsing elevated features of BPD and bipolar disorder.


METHODS
Subjects were 818 students enrolled in a state university. The study used self-report instruments to identify 21 participants with elevated features of mania and 30 subjects with significant BPD features. In addition, subjects completed a new self-report instrument to measure affective instability, the Affective Lability Questionnaire for Borderline Personality Disorder (ALQ-BPD).


RESULTS
Aggregate frequency and intensity scores, as well as the total scores on the ALQ-BPD, were significantly higher for subjects with elevated borderline traits than subjects with elevated bipolar traits. Subjects with borderline traits reported significantly more frequent affective shifts on seven of nine dimensions of the ALQ-BPD. Subjects with borderline traits reported significantly more intense affective shifts on two of nine dimensions. Both groups reported affective instability that was less than 50% reactive to interpersonal events, but subjects with borderline traits reported affective instability that was significantly more interpersonal than that reported by subjects with bipolar traits.


CONCLUSIONS
The affective instability associated with symptoms of BPD and bipolar disorder has different profiles, particularly with respect to frequency. Borderline affective instability appears more interpersonal than the affective instability associated with bipolar symptoms.
Laboratory for the Study of Adult Development, McLean Hospital, Department of Psychiatry, Harvard Medical School, Belmont, MA, USA.
D Bradford
DB
Reich
Mary C
MC
Zanarini
Christopher J
CJ
Hopwood
Katherine M
KM
Thomas
Garrett M
GM
Fitzmaurice
D000293:Adolescent; D000328:Adult; D000339:Affect; D000786:Anger; D001008:Anxiety Disorders / Q000150:complications / Q000523:psychology; D001714:Bipolar Disorder / Q000150:complications / Q000523:psychology*; D001883:Borderline Personality Disorder / Q000150:complications / Q000523:psychology*; D003866:Depressive Disorder / Q000150:complications / Q000523:psychology; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D008297:Male; D008875:Middle Aged; D057566:Self Report; D055815:Young Adult