Validating Psychiatric Diagnoses in UK Biobank

Diagnoses of anxiety and depression were retrieved from the UK Biobank hospital inpatient data (according to ICD-10 codes) [18 ] and primary care data (according to SNOMED CT, local EMIS codes, Clinical Terms Version 3, and Local TPP codes) [19 ]. The diagnoses of psychiatric disorders from HES in England have been validated, indicating a positive predictive value of up to 75% for depression and <60% for anxiety [20 (link)]. Prescription of psychotropic medications was ascertained through mapping the UK Biobank prescription codes (i.e., dm+d and local EMIS codes) to their corresponding active ingredients using dm+d XML Transformation Tool and UK Biobank Data-Coding 7678 resource [19 ]. The active ingredients were then matched to the WHO Atomical Therapeutic Chemical (ATC) classification system [21 ], and the ingredients (e.g., doxepin, esketamine) with more than one matched ATC codes were discarded as it is difficult to disentangle therapeutic targets. We extracted information (i.e., prescription code and date) about anxiolytics (N05B) and antidepressants (N06A) in the analysis. Supplementary Table S1 provides a list of the active ingredients and their corresponding ATC codes used in this study.