Dissociative experiences and panic disorder linked in bipolar patients
By Andrew Czyzewski
17 September 2008
J Affect Disord 2008; Advance online publication

Feelings of detachment from the external world, known as dissociative experiences, are associated with an early age of onset of bipolar disorder and may cluster with panic disorder comorbidity, study findings suggest.

Based on this new evidence, the team of researchers behind the study speculates that "bipolar-panic comorbidity seems to configure a unique entity from a clinical, neurobiological, and genetic point of view."

Depersonalization is defined as an experience in which the individual feels a sense of unreality and detachment from him/herself. Depersonalization is often associated with derealization, and consists of an alteration in the perception of one's surroundings so that sense of the reality of the external world is lost.

Both these phenomenon come under the more general term of dissociative symptoms.

"The aim of this study was to investigate frequency and clinical correlates of dissociative symptoms, with special attention to depersonalization symptoms, in bipolar disorder patients," Marco Mula (Amedeo Avogadro University, Novara, Italy) and co-workers explain.

They assessed 43 patients with bipolar I disorder and 48 with bipolar II disorder with the Semi-structured Clinical Interview for Temperament (TEMPS-I); the Dissociative Experiences Scale (DES); and the Structured Clinical Interview for Depersonalization-Derealization Spectrum (SCI-DER).

Lifetime dissociative symptoms were reported by 25.6% of bipolar I disorder patients and 25% of bipolar II disorder patients, defined by a score of more than 25 on the DES (the accepted cutoff score for pathological dissociation).

There was no difference between bipolar I disorder and bipolar II disorder patients in scores of any dissociative measurements.

Age of onset of bipolar disorder was negatively correlated with SCI-DER-total score (r=-0.436) and DES score (r=-0.270).

A logistic regression model showed that derealization scores, corrected for age and gender, were significantly associated with a diagnosis of comorbid panic disorder (OR=1.22).

"Our study suggests that lifetime depersonalization symptoms are correlated with an early onset of bipolar disorder and derealization symptoms with panic disorder comorbidity," the researchers conclude.

"The association with an early onset of the disease may suggest the need for further investigation to clarify whether bipolar disorder patients with lifetime depersonalization configure a separate clinical phenotype characterized by other indices of disease severity (e.g. number of hospitalization, number of episodes, treatment resistance)."