BIOLOGICAL AND CLINICAL MARKERS IN PSYCHOPATHOLOGY: FROM VULNERABILITY TO CATEGORICAL DISORDERS

Studying risk factors, trajectories, and outcomes of psychiatric disorders is crucial for improving their management and clarifying their causal links. Ultimately, the goal is to develop early intervention strategies that can mitigate the impact of clinically established conditions later in life. This requires a comprehensive understanding of the underlying psychopathological processes. Adolescence to early adulthood represents a particularly critical phase of vulnerability, during which the intertwined relationship between genetic and environmental factors shapes both brain development and behavioral patterns, potentially leading to the onset of psychiatric disorder. Within this developmental framework, my research aims to disentangle the extent to which genetic and environmental factors drive brain and behavioral differences in a young sample, employing twin analysis as a powerful method to explore these influences. Specifically, my thesis focuses on the early detection and prevention of severe psychiatric disorders, adopting a transdiagnostic approach and integrating genetic, environmental, biological, and economic perspectives. Through twin models, I investigated the genetic and environmental determinants of susceptibility states, employing both specifically designed questionnaires and potential biological biomarkers (i.e., L1 retrotransposons). Moreover, I examined the clinical and economic implications of implementing MRI in the routine evaluation of first-episode psychosis to rule out the “organic” form of psychosis. The psychopathological process was thus addressed at different stages and from multiple perspectives, with the common aim of better characterizing vulnerability states, facilitating early identification, and supporting timely interventions to modify illness trajectories.