Exploratory and confirmatory factor analyses of the structured interview for disorders of extreme stress

Two studies were conducted to provide the first empirical examination of the factor structure of a revised version of the clinically derived Structured Interview for Disorders of Extreme Stress, a structured interview designed to assess associated features of posttraumatic stress disorder (PTSD) thought to be related to early onset, interpersonal, and prolonged traumatic exposure. Five factors representing demoralization, somatic dysregulation, anger dysregulation, risk/self-harm, and altered sexuality were derived from an exploratory factor analysis conducted with adult trauma survivors in substance abuse treatment. They provided a good fit in a confirmatory factor analysis conducted in a second study with a nonclinical sample of ethnoculturally diverse, socioeconomically disadvantaged, incarcerated adults. Evidence of the derived factors' internal consistency and convergent and discriminant validity is reported. Evidence supported the association of these factors with interpersonal trauma (physical and/or sexual), its repetition, and its earlier onset. Implications for clinical assessment of complex posttraumatic stress disorder are discussed.