White Matter Connectivity in Youth at Risk for Serious Mental Illness: A Longitudinal Analysis.

Longitudinal changes in white matter connectivity were assessed in a sample of youth at-risk for serious mental illness (n=183; age 12-25). Diffusion tensor imaging (DTI) was acquired at baseline and 12 months from youth recruited across two sites and classified as healthy controls (n=36), familial risk (n=30), mild-symptoms (n=41), attenuated syndromes (n=70), or transition (n=9) based on clinical assessments. Fractional anisotropy (FA) and mean diffusivity (MD) values were derived for the whole brain white matter, forceps minor, anterior cingulate, anterior thalamic radiations, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, and uncinate fasciculus. MANCOVA analysis controlling for site, sex, and age showed no significant group differences in FA and MD at baseline or at 12 months. Linear mixed effects analysis showed a significant effect for time for most white matter tracts, but no effect for group, or group by time interaction. Transdiagnostic risk groups have similar profiles of WM connectivity and similar rates of change over time.

The role of a family history of psychosis for youth at clinical high risk of psychosis.

AIM: On average, there is a 10% to 12% likelihood of developing a psychotic disorder solely based on being at familial high risk. However, the introduction of the criteria for clinical high risk (CHR) of psychosis suggested for CHR individuals, 20% to 30% will go on to develop a full-blown psychotic illness within 3 years. Several studies suggest a role for family history in conversion to psychosis among those at CHR. However, we know very little about those who meet the CHR criteria and have a positive family history for psychosis compared to those at CHR with no known family history. The aim of this study was to compare these 2 groups on demographics, clinical symptoms, social and role functioning, IQ, environmental factors and conversion to psychosis. METHOD: A total of 762 participants met criteria for being at CHR, 119 of whom had a family history (CHR + FH) and 643 without (CHR-FH). Groups were compared on attenuated symptoms, role and social functioning, IQ, past trauma, perceived discrimination and cannabis use. Survival analysis was used to compare groups on conversion rates. RESULTS: There were no major differences between the groups in symptoms, functioning, IQ, cannabis use or in the rate of conversion between the groups. The CHR + FH group reported increased amounts of early trauma. CONCLUSION: There is a possibility that CHR + FH individuals believe that it is more difficult for them to cope with circumstances such as abuse or potential abuse. Future research on this subject should investigate family environment and its role in conversion to psychosis among CHR + FH individuals.