Psychotic-like experiences in adolescents enriched for high-risk for developing severe mental illness: change over two-years and associations with neural reward processing and affective symptoms.

Psychotic-like experiences (PLEs) -subclinical experiences or symptoms that resemble psychosis, such as hallucinations and delusional thoughts-often emerge during adolescence and are predictive of serious psychopathology. Understanding PLEs during adolescence is crucial due to co-occurring developmental changes in neural reward systems that heighten the risk for psychotic-related and affective psychopathology, especially in those with a family history of severe mental illness (SMI). We examined associations among PLEs, clinical symptoms, and neural reward function during this critical developmental period. Over two-years, 117 adolescents (aged 13-19 years at baseline) at high-risk (n = 74) or low-risk (n = 43) for SMI based on family history of affective or psychotic disorder completed symptom questionnaires annually and fMRI scanning at study entry during a guessing reward task. We assessed changes in PLEs over two-years and evaluated whether clinical symptoms (anxiety, depression, anhedonia) and response to rewards of the dorsal medial prefrontal cortex (dmPFC) and ventral striatum (VS) predicted PLEs two-years later. PLEs total scores and distress increased over time, with the high-risk group showing a greater rise in PLEs than the low-risk group. Heightened right VS neural activation and higher anxiety at baseline (but not left VS or dmPFC neural activation, depression, or anhedonia) predicted more PLEs at 24-months. Heightened vigilance and sensitivity to external stimuli may be important precursors to the development of PLEs for adolescents.