STratifying Resilience and Depression Longitudinally (STRADL): A depression-focused investigation of Generation Scotland, using detailed clinical, cognitive, and neuroimaging assessments

STratifying Resilience and Depression Longitudinally (STRADL) is a population-based study built on the Generation Scotland: Scottish Family Health Study (GS:SFHS) resource. The aim of STRADL is to subtype major depressive disorder (MDD) on the basis of its aetiology, using detailed clinical, cognitive, and brain imaging assessments. The GS:SFHS cohort provides an important opportunity to study complex gene-environment interactions, incorporating linkage to existing datasets and inclusion of early-life variables for two longitudinal birth cohorts – the Walker birth cohort, and Aberdeen Children of the 1950s (ACONF).

Access:
This dataset is held in the Edinburgh DataVault. De-identified data from this study is available to researchers through the GS:SFHS Access Committee ([email protected]). External users may request access to a copy of the data by contacting the Generation Scotland Access Committee.

Cohort basics: Participants who had already taken part in GS:SFHS between 2006-2011, and who were eligible for re-contact, were sent a postal invitation by the University of Dundee Health Informatics Centre. In Dundee (Tayside) recruitment targeted members of the Walker cohort, and in Aberdeen recruitment initially targeted members of ACONF. Recruitment has been completed and we consented and tested 1,188 participants (Aberdeen n = 582; Dundee n = 606) (Figure 1).

Follow-up and attrition: Of the initial 24,096 participants in GS:SFHS, 21,525 remained eligible for follow-up in STRADL. We invited 5,649 potential participants to take part in the study, of which 1,645 responded positively; however, 170 declined once they were contacted by our research team or withdrew before consenting. Some questionnaire and cognitive data were first assessed at the GS:SFHS baseline assessment between 2006-2011, thus providing longitudinal measures of depression and resilience. Similarly, routine NHS data and early-life variables are linked to STRADL data, further providing opportunities for longitudinal analysis.

Design and measures: Data collection in STRADL included the following: socio-economic and lifestyle variables; physical measures; questionnaire data that assessed resilience, early-life adversity, personality, psychological health, and lifetime history of mood disorder; laboratory samples for repeat genetic analysis and additional genomic analyses; cognitive tests; and structural and functional brain magnetic resonance imaging.

Unique features: STRADL data have been robustly collected on a wide range of key phenotypes that allow epidemiological study of depression and resilience in a population-based cohort. The MRI and detailed depression phenotyping protocol described here was cross-sectional; however, STRADL provides longitudinal measures of cognition, personality, and psychological health. This is because many of the cognitive tests applied in STRADL are the same as those used at the GS:SFHS baseline assessment, as well as some personality and mood measures. Similarly, routine NHS data, and ACONF and Walker cohorts’ early-life variables, is linked to STRADL data, further providing opportunities for longitudinal predictors on depression and resilience.

Habota, T et al. "Cohort Profile: STratifying Resilience and Depression Longitudinally (STRADL): A depression-focused investigation of Generation Scotland, using detailed clinical, cognitive, and neuroimaging assessments", (2019)Edinburgh DataVault. https://doi.org/10.7488/8f68f1ae-0329-4b73-b189-c7288ea844d7