Dimensional Psychopathology Explains Functional Disability better than ICD-10 Categories

The establishment of outcome measures that accurately reflect real-world recovery is a significant challenge in psychiatry. The present study aims to compare the explanatory power of traditional ICD-10 categorical diagnoses with dimensional psychopathology across functional, social, and cognitive domains. A total of 206 psychiatric patients diagnosed with ICD-10 diagnoses (F10–F69) were assessed using a transdiagnostic battery of self-reports and clinician-administered tools. Exploratory Factor Analysis (EFA) identified four psychopathological dimensions: dysregulation, reality distortion, detachment and substance use. Bayesian ANCOVAs were used to compare these dimensions and categorical diagnoses with respect to their ability to predict outcomes, including the WHODAS-II and ICF-3F-AT. The utilisation of dimensional models has been demonstrated to result in superior performance in terms of the efficacy with which they explain global functioning when compared with categorical diagnoses. Dysregulation emerged as the strongest predictor of functional impairment across all measures, followed by Detachment, which specifically predicted role execution and empathy. Conversely, categorical diagnoses provided insufficient predictive value. Evidence for both frameworks was anecdotal or favoured exclusion regarding cognitive performance and Theory of Mind. These findings advocate for a paradigm shift toward dimensional assessments in clinical practice to better capture patient recovery trajectories.