1250 Delusional Ideation in Young Adulthood is Associated with Grey and White Matter Alterations in Adolescence

Background and Aims Several studies have described an association between very preterm birth and psychiatric problems later in life. We aimed to investigate whether young adults who were born very preterm (VPT) (< 33 gestational weeks) are at increased risk of experiencing non-clinical psychotic symptoms compared to controls (e.g., delusional ideation) and whether such symptoms are associated with altered brain maturation. Methods Sixty-four VPT born individuals and 39 controls (mean age 20 years) completed the Peters’ Delusional Inventory, which measures psychosis proneness in the general population. Structural MRI data collected at age 15 years were used to investigated possible anatomical correlates of psychosis proneness, by subdividing the sample according to high (>=8; VPT: 40.6%, controls: 48.7%) and low (< 8) PDI scores. Results The groups did not differ in PDI scores (χ2=0.67, p=0.41). High PDI scores at 20 years were associated with structural brain alterations at 15 years. In controls, those with high PDI scores showed decreased grey matter volume in parahippocampal and middle occipital gyri and decreased white matter volume in inferior temporal gyrus and precuneus. In VPT-born individuals grey matter volume decreases were observed in those with high PDI scores in superior/medial frontal and middle temporal gyri and white matter volume decreases in insula. Conclusions High PDI scores in early adulthood are associated with region-specific structural brain alterations in mid-adolescence. Fronto-temporal alterations observed in the VPT group may reflect the neurodevelopmental vulnerability of this network, which has been implicated in the pathophysiology of delusions in psychosis.