What drives poor functioning in the at-risk mental state? A systematic review

Background: Transition to psychotic disorder has been the traditional outcome of interest for research in the at-risk mental state (ARMS). However, there is growing recognition that individuals with ARMS may function poorly regardless of whether they develop psychosis. We aimed to review the literature to determine whether there are specific factors associated with, or predictive of, functional impairment in the ARMS population.

Method: An electronic database search of MEDLINE, PsycINFO and Embase from inception until May 2014 was conducted using keyword search terms synonymous with the at-risk mental state and functioning. Eligible studies were original peer-reviewed English language research articles with populations that met validated at-risk diagnostic criteria and examined the cross-sectional or longitudinal association between any variable and a measure of functioning.

Results: Seventy-two eligible studies were identified. Negative symptoms and neurocognitive impairment were associated with poor functioning in cross-sectional studies. Negative and disorganised symptoms, neurocognitive deficits and poor functioning at baseline were predictive of poor functional outcome in longitudinal studies. Positive symptoms were unrelated to functioning in both cross-sectional and longitudinal studies. Functional disability was persistent and resistant to current treatments.

Conclusions: Negative and disorganised symptoms and cognitive deficits pre-date frank psychotic symptoms and are risk factors for poor functioning. This is consistent with a subgroup of ARMS individuals potentially having neurodevelopmental schizophrenia. Treatments aimed at improving functioning must be considered a priority on par with preventing transition to psychosis in the development of future interventions in the ARMS group.