Fig. 1: Analysis flowchart for the present study.

Flowchart describing the analyses undertaken following genetic and phenotypic quality control (see Methods) for each of the depression symptom items of the PHQ-9 in each of the four samples—UKB (the Mental Health Questionnaire and Experience of Pain Questionnaire), the GLAD Study and the PROTECT Study. MTAG, multi-trait analysis of GWAS; FUMA, functional mapping and annotation; LAVA, local analysis of [co]variant association; ADNI, Alzheimer’s disease neuroimaging initiative; PC, genetic principal components.