Figure 1.

The measures for depressive symptoms generated for this study. The x-axis represents each instance (0 = baseline, 1 = first repeated assessment, 2 = imaging assessment, and 3 = online follow-up, consistent with the coding for instances in UK Biobank [http://biobank.ctsu.ox.ac.uk/showcase/instance.cgi?id=2]). There were 4 measures generated: 1) cross-sectional measurement for depressive symptoms acquired with imaging assessment, 2) linear growth curve denoting longitudinal trajectory of depressive symptoms derived from 3 time points up until the imaging assessment, 3) mean of depressive symptoms generated based on at least 2 multiple assessments, and 4) variability of depressive symptoms, which was the SD of at least 3 time points. FA, fractional anisotropy; MD, mean diffusivity; PHQ4, Patient Health Questionnaire-4.