Evaluation of the validity and utility of a transdiagnostic psychosis dimension encompassing schizophrenia and bipolar disorder. (August 2016)

• Record Type: Journal Article
• Authors: Reininghaus, Ulrich; Böhnke, Jan R.; Hosang, Georgina; Farmer, Anne; Burns, Tom; McGuffin, Peter; Bentall, Richard P.
• Is Part Of: British journal of psychiatry. Volume 209:Number 2(2016)
• Page Start: 107
• Page End: 113
• Publication Date: 2016-08
• Subjects: Psychiatry -- Periodicals; Psychology, Pathological -- Periodicals; 616.89005
• DOI: 10.1192/bjp.bp.115.167882
• Languages: English
• ISSNs: 0007-1250

Abstract

Abstract : Background: In recent years, the Kraepelinian dichotomy has been challenged in light of evidence on shared genetic and environmental factors for schizophrenia and bipolar disorder, but empirical efforts to identify a transdiagnostic phenotype of psychosis remain remarkably limited. Aims: To investigate whether schizophrenia spectrum and bipolar disorder lie on a transdiagnostic spectrum with overlapping non-affective and affective psychotic symptoms. Method: Multidimensional item-response modelling was conducted on symptom ratings of the OPerational CRITeria (OPCRIT) system in 1168 patients with schizophrenia spectrum and bipolar disorder. Results: A bifactor model with one general, transdiagnostic psychosis dimension underlying affective and non-affective psychotic symptoms and five specific dimensions of positive, negative, disorganised, manic and depressive symptoms provided the best model fit and diagnostic utility for categorical classification. Conclusions: Our findings provide support for including dimensional approaches into classification systems and a directly measurable clinical phenotype for cross-disorder investigations into shared genetic and environmental factors of psychosis.