Oral Session 1 Thursday, October 20, 1:00–2:30 p.m., Parini Adolescence and Anomalous Self-Experiences Chair: Paolo Fiori Nastro 1 , Co-Chair: Andrea Raballo 2 Speakers: Frauke Schultze-Lutter, Stephen J. Wood, Stefanie J. Schmidt, Martin Debbané, Nella Lo Cascio, Maya Rothbaum, Nel- son Barnaby, David C. Cicero 1 Department of Neurology and Psychiatry, Sapienza University of Rome, Italy, 2 University of Oslo, Norway Talk 1 Basic Symptoms in the General Population and their Association with Age Frauke Schultze-Lutter 1 , Stephan Ruhrmann 2 , Chantal Michel 1 , Stefanie J. Schmidt 1 , Jochen Kindler 1 , Benno G. Schimmelmann 1 1 University of Bern, Switzerland, 2 University of Cologne, Germany Recently, limited psychopathological significance of attenuated psy- chotic symptoms before the turn from early to late adolescence, i.e., age 15/16, was reported, which emphasizes the potentially important role of neurodevelopmental aspects in the early detection of psychoses. Thus, we examined the age effect on prevalence and clinical significance of 14 cognitive and perceptive basic symptoms (BS) included in risk criteria of psychosis in a randomly selected rep- resentative 8- to 40-year-old general population sample (N = 689). Participants underwent clinical interviews for BS, psychosocial func- tioning, and current mental disorder on the telephone. BS were reported by 18% of participants, mainly cognitive BS (15%). Age seemed to affect perceptive and cognitive BS differently, indicating an age threshold for perceptive BS in late adolescence (around age 18) and for cognitive BS in young adulthood (early twenties)–with higher prevalence, but a lesser association with functional deficits and the presence of mental disorder in the below-threshold groups. Thereby, effects of the interaction between age and BS on function- ing and mental disorder were commonly stronger than individual effects of age and BS. Supporting the proposed substrate-closeness of BS, differential age effects of perceptual and cognitive BS seem to follow normal brain maturation processes, in which they might occur as infrequent and temporary non-pathological disturbances. Their persistence or occurrence after the conclusion of main brain matura- tion processes, however, might signify aberrant maturation processes. Thus, BS might provide important insight into the pathogenesis of psychosis and into potential neuroprotective targets. Talk 2 Adolescent Brain Development and the Onset of Psychosis Stephen J. Wood University of Birmingham, UK Adolescence is a formative period of human development that is characterized by increases in affective reactivity, greater interest in and sensitivity towards peer-relationships, and an enhanced capacity to engage in behaviour directed towards long term goals. The devel- opmental changes through this period promote the skills necessary for greater independence and enhance new forms of peer attach- ment, but they also create greater vulnerability to emotional and behavioural dysregulation. Indeed, the peak age of onset for psy- chotic illnesses is between 15 and 25, roughly equating to late ado- lescence. To demonstrate the importance of the adolescent developmental period for psychosis onset, epidemiological, cognitive, and brain imaging studies will be reviewed. Own as well as other studies provide significant evidence that adolescent onset of psycho- sis is associated with greater genetic loading, premorbid social impair- ments, more severe premorbid neurodevelopmental abnormalities, longer duration of untreated psychosis, a more severe clinical course and more severe negative symptoms. Furthermore, higher cognitive functions fail to show age appropriate gains during adolescence in those who later develop psychosis, while brain imaging data indicates faster maturation of grey matter regions. In conclusion, understanding the link between adolescence and the onset of psychosis, including the relationship with abnormal developmental trajectories of func- tional and structural brain networks, will assist in the search for bio- markers for the development of such illnesses. DOI 10.1111/eip.12396 62 © 2016 The Authors Early Intervention in Psychiatry © 2016 Wiley Publishing Asia Pty Ltd Early Intervention in Psychiatry 2016; 10 (Suppl. 1): 62–117 wileyonlinelibrary.com/journal/eip Early Intervention in Psychiatry October 2016; 10 (Suppl. 1): 62–117