TWIN STUDY OF DISSOCIATIVE EXPERIENCE

The relative influence of genetic and environmental influences on meas ures of pathological and nonpathological dissociative experience was e stimated using a classic twin-study design. Subjects were 177 monozygo tic and 152 dizygotic volunteer general population twin pairs who comp leted two measures of dissociative capacity identified hom the items c omprising the Dissociative Experiences Scale (DES). Additive genetic i nfluences accounted for 48% and 55% of the variance in scales measurin g pathological and nonpathological dissociative experience, respective ly. Heritability estimates did not differ by gender. The genetic corre lation between these measures was estimated at .91, suggesting common genetic factors underlying pathological and nonpathological dissociati ve capacity. Genetic and environmental correlations between the DES sc ales and measures of personality disorder traits (Dimensional Assessme nt of Personality Pathology-Basic Questionnaire; DAPP-BQ) were also es timated. Significant genetic correlations (median = .38) were found be tween the DES scales and DAPPB & cognitive dysregulation, affective la bility, and suspiciousness, suggesting that the genetic factors underl ying particular aspects of personality disorder also influence dissoci ative capacity.