Clinical Differentiation of Bipolar II Disorder From Borderline Personality Disorder

Adam Bayes; Gordon Parker; Kathryn Fletcher


Curr Opin Psychiatry. 2014;27(1):14-20. 

In This Article


Impulsivity is defined as a tendency for rapid, unplanned behaviours,[45] and to act on urges without regard to consequences.[46] It may be a partially heritable trait[2] and can occur periodically as a state phenomenon. Although impulsivity may represent a shared phenotype of bipolar and BPD,[2] nuances in its differential expression have been suggested.

Impulsivity may represent both a trait and state feature of bipolar disorder.[47] Benazzi[48] quantified a trait impulsivity rate of 41% in remitted BP II outpatients, indicating that it is not specific to BPD. In BP II, however, episode-based impulsivity is more commonly associated with hypomanic as against depressive BP II mood states.[32] Impulsivity during hypomania has also been modelled as lying on a continuum with inter-episode trait impulsivity.[48–51]

Impulsivity is a core diagnostic feature of BPD and may represent a way of managing negative emotions by distraction or relief from intense negative affect[52] rather than relate to any mood-related disinhibition characterizing bipolar. In BPD, impulsivity tends to be more enduring,[53] although Zanarini et al.[54] reported it as the feature most likely to remit.

Several studies have directly compared impulsivity in BP II and BPD, revealing differing features. Higher scores on the Barratt Impulsiveness Scale[55] were quantified in BPD relative to BP II patients.[34] In another study, those with BP II tended towards the 'attentional impulsiveness' associated with cognitive disturbances (including impaired concentration, distractibility and racing thoughts), in contrast with motor and 'nonplanning impulsiveness' characterized by difficulty planning actions and thinking about consequences observed in those with BPD.[32] More recently, differing phenomenological impulsivity profiles were reported in BPD and BP II patients, with a trend towards higher scores on the Urgency and (lack of) Perseverance subscales of the Urgency, Premeditation, Perseverance and Sensation Seeking Impulsive Behavior Scale[56] in the former group.[57]