RT Journal Article SR Electronic T1 Longitudinal trajectories of brain age in young individuals at familial risk of mood disorder JF bioRxiv FD Cold Spring Harbor Laboratory SP 537951 DO 10.1101/537951 A1 Laura de Nooij A1 Mathew A. Harris A1 Emma L. Hawkins A1 Xueyi Shen A1 Toni-Kim Clarke A1 Stella W.Y. Chan A1 Tim B. Ziermans A1 Andrew M. McIntosh A1 Heather C. Whalley YR 2019 UL http://biorxiv.org/content/early/2019/10/17/537951.abstract AB Background Within young individuals, mood disorder onset may be related to changes in trajectory of brain structure development. To date, however, longitudinal prospective studies remain scarce, showing partly contradictory findings, with a lack of emphasis on changes at the level global brain patterns. Cross-sectional adult studies have applied such methods and show that mood disorders are associated with differential aging trajectories, or accelerated brain ageing. Currently, it remains unclear therefore whether young individuals show differential brain structure ageing trajectories associated with onset of mood disorder and/or presence of familial risk.Methods Participants included young individuals (15-30 years, 53% F) from the prospective longitudinal Scottish Bipolar Family Study (SBFS) with and without a close family history of mood disorder. All were well at time of recruitment. Implementing a structural MRI-based brain age prediction model we globally assessed individual trajectories of age-related structural change with use of the difference between predicted brain age and chronological age (brain-predicted age difference; brain-PAD) at baseline and at two-year follow-up. Based on follow-up clinical assessment, individuals were categorised into three groups: (i) controls who remained well (C-well, n = 93), (ii) high familial risk who remained well (HR-well, n = 74) and (iii) high familial risk who developed a mood disorder (HR-MD, n = 35).Results At baseline, brain-PAD was comparable between groups. Results showed statistically significant negative trajectories of brain-PAD between baseline and follow-up for HR-MD versus C-well (β = - 0.60, pcorrected < .001) and HR-well (β = −0.36, pcorrected = .02), with a potential intermediate trajectory for HR-well (β = −0.24 years, pcorrected = .06).Conclusions These findings suggest that within young individuals, onset of mood disorder and familial risk may be associated with a deceleration in brain structure ageing trajectories. Extended longitudinal research will need to corroborate findings of emerging maturational lags in relation to mood disorder risk and onset.