The DELTA Study: DisEntangling the aetiological complexity of psychosis: A Life course Trajectories Approach

Psychotic disorders, such as schizophrenia, often cause considerable distress and disability. They are also highly heterogeneous, with substantial variations in age of onset, symptoms, course, outcome and treatment responses among individuals and across populations. Understanding this heterogeneity is essential to developing more effective treatments for psychoses. In this programme, we will disentangle this heterogeneity across three Workstreams (WS1-WS3) and two cross-cutting Platforms that integrate lived experience (P1) and support innovation in statistical methods (P2). WS1-3 will harness causal inference methods across a unique combination of population cohorts and global clinical datasets to generate transformative insights on risks for and outcomes of psychosis across the lifecourse. We will investigate how biopsychosocial risk and protective factors interact and cluster to influence the onset, presentation, and outcomes of psychosis. We will examine how these causal pathways differ across by generation, place, sex, and ethnic group. This work will be enriched by lived experience-led research exploring how people with psychosis understand and make sense of causes and outcomes of psychosis. We will deliver longitudinal data resources for the scientific community, transform understandings of the aetiological heterogeneity of psychoses, and create a lived experience-led blueprint for ethical implementation of a cause-based approach to treatment.