Predicting the evolution from first-episode psychosis to mood or psychotic disorder: A systematic review of biological markers

The development of paraclinical tools to assist clinical assessment is already widespread in nearly all other medical specialties. In psychiatry, many efforts are being made to improve management strategies using these new techniques. The first episode psychosis (FEP) is a clinical entity whose evolution after onset is difficult to predict in the current state of our practices. Our main objective was to identify from the literature the most promising biological markers for early prediction of thymic or psychotic trajectories following FEP. We performed a systematic literature review on 4 databases: PubMed, Scopus, PsycINFO, and Web of Science following PRISMA guidelines and using search terms related to FEP and biomarkers. Eight studies were included in our final analysis. Several biomarkers showed promising discriminatory capacities for predicting post-FEP evolution: the interleukins IL-6, IL-12p40, IL-1β, and the mRNA expression levels of the DICER-1 and AKT-1 genes. Other studies that opted for broad-spectrum strategies also highlighted new leads for the discovery of additional biomarkers. Overall, our results indicate the value of replicating studies targeting the analysis of the predictive capacities of several biological markers. It also appears important to homogenize methodologies and favor the construction of predictive models on several of these markers to reinforce their statistical significance. •Interleukins IL-6, IL-12p40, IL-1β, and expression levels of AKT-1 and DICER-1 genes can be promising biomarkers in FEP.•Studies suggest distinct inflammatory profiles at baseline depending on thymic or non-thymic evolution after FEP.•Identified biomarkers could support early and personalized management of FEP populations.•Standardizing research methodologies is essential to enhance the clinical relevance of these biomarkers.