The psychometric properties of the adolescent dissociative experiences scale (A-DES) in a sample of Portuguese at-risk adolescents.

Dissociation is a process that often occurs as a sequela of psychological trauma, and it is interrelated with psychological and behavioral problems. In the at-risk adolescent population, dissociation is often underdiagnosed and undertreated. Having reliable measures to assess this phenomenon can help in identifying adolescents at-risk and improve treatment outcomes. This study assessed the psychometric properties of the Adolescent Dissociative Experiences Scale (A-DES) with a sample of 402 Portuguese adolescents recruited from three at-risk populations. Participants completed self-report measures of trauma exposure, posttraumatic symptoms, psychological and behavioral problems, and the A-DES. A subset of the sample also completed test-retest measures. Confirmatory factor analyses revealed a best-fitting 3-factor model. Analyses revealed good internal consistencies and good agreement test-retest reliability for the scale overall and the factor-based sub-scales. Construct and predictive validity was supported with results showing that A-DES discriminates between youth reporting high versus low levels of cumulative trauma exposure and youth who meet or do not meet criteria for a probable PTSD diagnosis. Study findings replicate prior research supporting a 3-factor model of dissociation and the usefulness of A-DES to identify adolescents with dissociative symptoms. Clinical and research implications are discussed.