Borderline patients have difficulties describing feelings; bipolar II patients describe difficult feelings. An...

Apparent similarities between borderline personality disorder (BPD) and bipolar II disorder (BIP-II) contribute to clinical difficulties in distinguishing between the disorders. Here, we aimed to explore how subjective Difficulties with the Identification and Description of Feelings (DIDF), a major constituent of the alexithymia construct and assessed as a part of the Toronto Alexithymia Scale (TAS), are related to relationship problems and health complaints in these groups.

Twenty-two patients with BPD; 22 patients with BIP-II; and 23 healthy controls (HC) completed TAS. Health complaints, including symptoms associated with mood swings, were assessed with the Giessener Subjective Complaints List (Giessener Beschwerdebogen-GBB), and relationship problems with the Health of the Nation Outcome scale, Relationship item (HoNOSR). Bivariate correlations were run.

Both patient groups had high DIDF and GBB scores. In BPD only, there was a significant positive correlation between DIDF and HoNOSR. In BIP-II only, there was a significant positive correlation between DIDF and GBB total score. In BIP-II, DIDF correlated highly with those GBB subscales assessing symptoms typically occurring during bipolar mood swings (cardiovascular and gastrointestinal symptoms, exhaustion).

Our results suggest that in BPD, high DIDF scores represent genuine problems with identifying and describing emotions which are expected to correlate with relationship problems. In BIP-II, high DIDF scores could potentially represent difficulties with understanding the unpredictable symptoms of bipolar mood swings. The findings suggest that difficulties with identifying and describing feelings in patients should be carefully explored to increase the validity of the diagnostic evaluation.