The 3 domains (3D) model of psychopathology in schizophrenia hypothesizes that positive, negative, and disorganized symptoms form mutually independent structures when symptom ratings are factor-analyzed. Using 6-category response data from the DSM-IV Field Trial for Schizophrenia and Related Disorders, Ratakonda et al1 have argued that this structure is generalizable to other psychotic disorders. As evidence, they presented a descriptive comparison of Varimax-rotated solutions (Varimax Information Systems Inc, Saskatoon, Saskatchewan) from separate principal components analyses of a subgroup of patients (n = 221) diagnosed as having DSM-III-R schizophrenia and a second heterogeneous subgroup (n = 189) composed of patients with other DSM-III-R psychotic disorders.
Dudgeon P, Mackinnon AJ, Bell RC, McGorry PD. Failure to Confirm the 3 Domains Model of Psychosis. Arch Gen Psychiatry. 2001;58(1):94-96. doi: