Depersonalization/derealization and its relationship to mood and anxiety disorders in the National Comorbidity Survey-Replication (NCS-R).

Background: Depersonalization/derealization (dpdr) is known to occur across mood and anxiety disorders (MAD) and has been proposed as a marker of worse illness. However, despite the well-known clinical association, there are no epidemiological data on the relationship between dpdr and MAD.

Method: In this NCS-R analysis clinically significant dpdr (DPDR-C) was defined as "sometimes" or "often" past-month endorsement of depersonalization and/or derealization in the absence of other pathological dissociation. Six past-month MAD diagnoses were examined: DSM-IV generalized anxiety disorder, panic disorder, social phobia, major depression, bipolar I, and bipolar II.  RESULTS: National DPDR-C one-month prevalence was 0.9%. After excluding all cases with past-month posttraumatic stress disorder or non-dpdr pathological dissociation, 21.2% of DPDR-C cases were accounted for by MAD while 3.0% of MAD cases endorsed DPDR-C, ranging from 0% (generalized anxiety disorder) to 11.8% (comorbid mood and anxiety disorder). DPDR-C was not uniquely related to any MAD disorder, and was not associated with MAD age of onset, chronicity, or impairment. Rather, DPDR-C was significantly associated with number of comorbid MAD disorders and with mood/anxiety comorbidity.

Conclusion: At the epidemiologic level DPDR-C was uncommon in MAD but was more likely to occur in the presence of combined mood and anxiety disturbance, which may cause greater disruption to the usual sense of self and thus trigger unreality experiences.