Studies in adolescents on ultra-high risk (UHR) and basic symptoms (BS) criteria for psychosis prediction are scarce. In Italy, early interventions in psychosis are less widespread than in other European countries. In the present study, we (1) assessed the clinical relevance of a UHR diagnosis [according to the comprehensive assessment of at-risk mental states (CAARMS) criteria] to promote the implementation of specific services for UHR adolescents into the Italian health care system; (2) described severity of positive, negative, general, and basic symptoms in UHR adolescents compared to adolescents with first-episode psychosis (FEP) and non-UHR adolescents (i.e., individuals who did not meet CAARMS criteria for UHR or FEP); and (3) investigated the predictive validity of UHR criteria in relation to BS criteria. Seventy-nine adolescents (aged 13-18 years) were assessed with the CAARMS, the positive and negative syndrome scale (PANSS), and the schizophrenia proneness instrument, child and youth version (SPI-CY). Both UHR (n = 25) and FEP (n = 11) had significantly higher PANSS subscale scores compared to non-UHR (n = 43). UHR had significantly lower PANSS-positive symptom scores than FEP, but similar global functioning and PANSS-negative symptoms and general psychopathology scores. Compared to non-UHR, both FEP and UHR had more severe thought and perception BS disturbances, and significantly more often met BS criteria. After 12 months, 2 of 20 (10%) UHR had transitioned to psychosis. They also met both BS criteria. Given the uncertain outcome of UHR adolescents, future research is needed to determine whether the combined assessment of BS with UHR symptoms can improve the accuracy of psychosis prediction in adolescence.
Keywords: Adolescents; Basic symptoms; Early detection; Early-onset psychosis; Ultra-high risk.