Borderline personality characteristics aid bipolar depression diagnosis

Young adults with bipolar depression exhibit significantly higher levels of borderline personality pathology than those with unipolar depression, say researchers who found that certain borderline characteristics could help clinicians to distinguish between bipolar and unipolar depression.

"From a clinical perspective, these data argue strongly for careful consideration of a primary bipolar illness in young adults with recurrent depression who appear to exhibit strong borderline features during their depressive episodes," note Daniel Smith and colleagues from the University of Edinburgh in Scotland the UK.

For their study, published in the Journal of Affective Disorders, the team recruited 87 young adults currently experiencing an episode of major depression and who had experienced at least one previous episode of depression.

Based on the diagnostic criteria for the Structured Clinical Interview for DSM-IV and the recently proposed structured diagnostic criteria for bipolar spectrum disorder, the participants were divided into three groups: 14 had bipolar affective disorder, 27 had bipolar spectrum disorder, and 46 had major depressive disorder.

All the groups were well matched for age, gender distribution, ethnicity, socioeconomic and educational status, age at onset of illness, and severity of index depressive episode.

However, the median number of borderline characteristics, measured using the International Personality Disorders Examination (IPDE), differed significantly among the groups.

Patients in the two bipolar groups reported a median number of six borderline characteristics, while patients with major depressive disorder reported a median of 4.5.

Moreover, Smith and team found that three questions on the IPDE were sufficient to distinguish between bipolar and unipolar depression.

These questions were: "Giving in to some of my urges gets me into trouble;" "I've never threatened suicide or injured myself on purpose;" "I have tantrums or angry outbursts." The sensitivity values of these questions for detecting bipolar depression were 0.76, 0.93, and 0.66, respectively.

The researchers therefore conclude: "The three borderline screening questions identified above, which might be considered to reflect cyclothymic characteristics or intra-episode hypomanic symptoms, are potentially useful to clinicians in the diagnostic assessment of this important patient group."

J Affect Disord 2005; 87: 17-23