S21. CORRELATES AND TRANSITION RATE OF CHILDREN AND ADOLESCENTS WITH ATTENUATED PSYCHOTIC SYMPTOMS: FINDINGS FROM A LONGITUDINAL STUDY

BACKGROUND: The identification of people at high risk of developing psychosis is one of the most promising strategies to improve outcomes. However, in children and adolescents research on the high risk state and attenuated psychotic symptoms is still in its infancy and the clinical validity of at risk criteria appears understudied in this population (Tor et al. 2018). Thus, in this longitudinal cohort study, we aimed to: (1) characterize the clinical profile of APS adolescents, adolescents suffering from early onset psychosis (EOP) and adolescents with psychiatric disorders other than APS and EOP (non-APS) and (2) to calculate the cumulative transition rate to psychosis at follow-ups and investigate predictors of conversion to psychosis. METHODS: Help-seeking adolescents (aged 12–18 years) consecutively admitted to Child and Adolescent Neuropsychiatric inpatient and outpatient units of the IRCCS Mondino Foundation (Pavia, Italy) were recruited. The Comprehensive Assessment of At-Risk Mental State (CAARMS) was used in order to evaluate the presence of attenuated or full-blown psychotic symptoms. The final sample consisted of 31 EOP, 110 APS and 102 non-APS adolescents. At baseline patients underwent an extensive clinical and, in a subset, also neuropsychological assessment using standardized semi-structured interviews and instruments. All APS patients recruited until March 2019 were followed up for a median period of 33 months (range 4–81 months) and baseline measures were repeated (every 12 months). Transition to psychosis was defined according to the CAARMS criteria. RESULTS: At baseline, APS status was associated with poor socio-occupational functioning, especially social functioning (p<0.0001), as well as clinical severity (p<0.0001) as assessed by clinicians. APS adolescents reported a higher level of suicidality compared to non-APS (p=0.0003). The APS group displayed a higher number of comorbid disorders compared to the EOP and non-APS (p<0.0001) and was related to a wide range of disorders. APS and non-APS adolescents did not significantly differ in any of the neuropsychological test administered, although a worsening trend was observed between the two groups with lower scores in APS adolescents. The cumulative proportion of psychosis transition in the APS group was 13%, 17%, 24.2% and 26.8% at 1,2,3 and 4-year follow-ups, respectively. A high percentage of APS patients received at least one psychotropic medication (62.1%) during the follow-up period, especially antipsychotics (43.7%). Baseline lower global and social functioning (p=0.0092), higher clinical severity (p<0.0001), negative symptoms, lower Total IQ (p=0.02) and Processing Speed Index (p=0.03) were associated with transitioning to psychosis at follow-ups. DISCUSSION: Our findings support the validity and clinical relevance of the identification of APS in children and adolescents. Indeed, in our sample APS adolescents suffer from a variety of comorbidities and non-psychotic symptoms, present higher suicidality and are markedly impaired compared to non-psychotic adolescents not fulfilling APS criteria. Moreover, they show a cumulative transition risk to psychosis of 26.8% at 4 years that, although being lower than that found in adult samples, is still comparable to that of other conditions in preventive medicine.