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

Abstract

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 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. Specifically, data collection in STRADL included: socio-economic and lifestyle variables; physical measures; questionnaire data that assesses resilience, early-life adversity, personality, psychological health, and lifetime history of mood disorder; laboratory samples; cognitive tests; and brain magnetic resonance imaging. Some of the 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. Recruitment has been completed and we consented and tested 1,188 participants.

Structural brain correlates of serum and epigenetic markers of inflammation in major depressive disorder

“…The participants in this study were recruited as part of the ‘STratifying Resilience and Depression Longitudinally’ (STRADL) study (2015–2019) which re-contacted participants from the Generation Scotland: Scottish Family Health Study (GS) via post for further assessment of mental health, specifically depression. Full details of the STRADL cohort and GS protocol are published elsewhere ( Habota et al, 2019 , Navrady et al, 2018 , Romaniuk et al, 2019 , Rupprechter et al, 2020 , Smith et al, 2013 , Stolicyn et al, 2020 ). A total of 880 unrelated participants were included in this study, 880 individuals had serum CRP and symptoms data, 796 individuals had both serum CRP and T1 neuroimaging data, and of these 764 individuals also had diffusion MRI (DTI) data.…”

“…A full medical history was obtained and updated from previous GS baseline assessment ( Smith et al, 2013 ) and any new diagnoses or medical episodes recorded at the imaging assessment. Health and lifestyle data were also collected, as were physical measurements such as height and weight, from which BMI was derived as a covariate of interest ( Habota et al, 2019 ). Smoking status was collected from GS baseline assessments as were the number of smoking pack years- full details have been reported by Barbu and colleagues ( Barbu et al, 2020 ).…”

“…In Aberdeen, participants were imaged on a 3 T Philips Achieva TX series MRI system (Philips Healthcare, Best, Netherlands) with a 32-channel phased-array head coil with a back-facing mirror (software version 5.1.7; gradients with maximum amplitude 80 mT/m and maximum slew rate 100. Both study centres followed the same protocol including structural sequences ( Habota et al, 2019 ). 3T MRI scans were anonymised at the time of acquisition and only the T1 and DTI data are utilized in this study.…”

DNA methylation signatures of C-reactive protein associations with structural neuroimaging measures and major depressive disorder

“…The participants in this study were recruited as part of the STratifying Resilience and Depression Longitudinally (STRADL) study (2015-2019) which re-contacted participants from the Generation Scotland: Scottish Family Health Study (GS) via post for further assessment of mental health, specifically depression. Full details of the STRADL cohort and GS protocol are published elsewhere [32][33][34][35][36][37] . The current sample included a range of 566-798 participants depending on the biomarker/imaging modality investigated (Table 1).…”

“…A full medical history was obtained and updated from previous GS baseline assessment 34 and any new diagnoses or medical episodes recorded at the imaging assessment. Health and lifestyle data were also collected, as were physical measurements such as height and weight, from which BMI was derived as a covariate of interest 32 . Smoking status was collected from GS baseline assessments as were the number of smoking pack years-full details have been reported by Barbu and colleagues 31 .…”