Avshalom Caspi, Renate M. Houts, Daniel W. Belsky, Sidra J. Goldman-Mellor, HonaLee Harrington, Salomon Israel, Madeline H. Meier, Sandhya Ramrakha, Idan Shalev, Richie Poulton, Terrie E. Moffitt*
Mental disorders have traditionally been viewed as distinct categorical entities, but the large number of people with comorbid disorders challenges this view. Participants who were part of the Dunedin Multidisciplinary Health and Development Study were assessed for mental health disorders between ages 18 and 38. The authors tested several models using confirmatory factor analysis and found that a three-factor model comprised of an internalizing, an externalizing, and a thought disorder factor fit the data well. The data was also well explained by one single general psychopathology dimension, which the researchers named the “p factor.” A single-factor view of psychopathology may help explain why it has been so difficult to find causes, biomarkers, and treatments for individual mental disorders.