When Did Posttraumatic Stress Disorder Get So Many Factors? Confirmatory Factor Models Since DSM–5

For over three decades confirmatory factor analysis (CFA) has been used to test the construct validity of models of posttraumatic stress disorder (PTSD). The four symptom dimensions of PTSD in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM–5) are based on CFA. Since the publication of DSM–5, the number of proposed factors has grown from four to seven. We review these models, focusing on (a) the number of symptoms per factor, indicating how well factors are identified; (b) correlations between factors, indicating how distinct they are; and (c) their external validation. Of the 27 CFAs published since 2013, almost all included factors composed of only two symptoms, and most relied on more than one. High factor correlations were the norm. Two thirds of models provided external validation. Discussion concerns implications for PTSD’s measurement and construct validity and recommendations for improving CFA in the PTSD literature