Clinical Edge

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Identifying Psychosis Biotypes

Neurobiological schemes vs clinical categorization

Clinically similar psychosis manifestations may emerge from different pathways, explaining the diversity seen in labs on the same biomarker variables when DSM diagnoses are used, according to a study involving 1,872 individuals.

Investigators collected a large biomarker panel on individuals with schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis (n=711), their first-degree relatives (n=883), and healthy controls (n=278). They used biomarker variance across paradigms to create variables that were used to capture neurobiological variance among the psychosis cases.

Multivariate analyses identified 3 neurobiologically distinct psychosis biotypes that did not respect clinical diagnosis boundaries. When using DSM, a single severity continuum was evident (schizophrenia worse than schizoaffective disorder worse than bipolar psychosis), but this was not the case for biotypes.

External validating measures supported these distinct subgroups vs clinical diagnosis. The authors noted a possible advantage of neurobiological schemes vs clinical categorization.

Citation: Clementz B, Sweeney J, Hamm J, et al. Identification of distinct psychosis biotypes using brain-based biomarkers. [Published online ahead of print December 7, 2015]. Am J Psychiatry. doi: http://dx.doi.org/10.1176/appi.ajp.2015.14091200.