Table 1.
Depression and environmental moderator phenotypes.
| Depression phenotypes† | ||
|---|---|---|
| Phenotype | Description | Sample size |
| Estimated lifetime depression diagnosis | Binary indicator of lifetime DSM-V depression diagnosis assessed in UKBB online mental health follow-up questionnaire. To meet criteria, participants had to endorse at least four of eight DSM-V depression symptoms (motor agitation/retardation symptom was not assessed), as well as duration, frequency, and impairment criteria. |
n = 115,458 85,513: controls 29,945 cases |
| Current depression severity | Sum score of all nine DSM-V depression symptom severities (using four point Likert scale to index severity of each symptom) over the two weeks leading up to assessment. Assessed in UKBB online mental health follow-up questionnaire. |
n = 115,463 sx = 3.347 |
| Conditional lifetime symptom count | Sum of symptom indicators for eight of nine lifetime DSM-V depression symptoms (motor agitation/retardation symptom was not assessed) among individuals endorsing lifetime incidence of a two+ week period characterized by anhedonia and/or depressed mood (questionnaire skip patterns necessitated this precondition). Assessed in the UKBB online mental health follow-up questionnaire. |
n = 62,138 sx = 1.745 |
| Lifetime episode count | Ordinal measure of incidence/recurrence of a two+ week period characterized by anhedonia and/or depressed mood indicating zero episodes, a single episode, or recurrent episodes. Assessed in UKBB online mental health follow-up questionnaire. |
n = 115,457 55,388: zero 30,724: single 26,345: recurrent |
| Touchscreen probable lifetime diagnosis, ordinal classification | Ordinal measure of depression diagnostic status based on a selection items of items from the Patient Health Questionnaire (62), the Structured Clinical Interview for DSM-IV Axis I Disorders-Research Version (63), and items assessing treatment seeking behavior specific to the UKBB touchscreen interview, as described in Smith et al., 2013 (64). Categories included no depression, single depressive episode, recurrent episodes (moderate), and recurrent episodes (severe), in that order. Assessed as part of the UKBB initial touchscreen interview. |
n = 91,121 66,605: controls 6,209: 1 episode 11,634: ≤ 2 moderate 6,633: ≥ 2 severe |
| Touchscreen probable lifetime diagnosis | Dichotomized coding of the touchscreen probable life diagnosis ordinal classification, contrasting no depression with the three diagnosis categories. |
n = 91,121 66,605: controls 84,516: cases |
| Severe recurrent depression | Binary indicator of case/control status for depression excluding cases and controls with mild to moderate depression symptoms. Controls were individuals who failed to endorse incidence of a two+ week period characterized by anhedonia and/or depressed mood. Cases were individuals met criteria for estimated lifetime depression diagnosis, endorsed at least five of the eight measured DSM-V symptoms, and experienced recurrent depressive episodes. Assessed in UKBB online mental health follow-up questionnaire. |
n = 64,432 53,218: controls 14,214: cases |
| PGC lifetime depression diagnosis | Binary indicator of lifetime depression diagnosis as measured in the PGC2 depression GWAS (19). The current investigation utilized data from the full expanded cohort meta-analysis, excepting UK-based cohorts (UKBB and Generation Scotland). |
n = 443,264 323,063: controls 120,201: cases |
| Moderator phenotypes‡ | ||
| Phenotype | Description | Sample size |
| Childhood trauma | Binary indicator of sexual and or physical abuse during childhood. Assessed in the UKBB online mental health follow-up questionnaire. |
n = 157,146 118,800: unexposed 38,346: exposed |
| Adult trauma | Binary indicator of any of the following traumatic events during adulthood: physical assault, sexual assault, witness to sudden/violent death, diagnosis with life threatening illness, involvement in life threatening accident, and exposure to combat or war-zone conditions. Assessed in the UKBB online mental health follow-up questionnaire. |
n = 157,223 64,286: unexposed 92,937: exposed |
| Recent trauma | Binary indicator of whether any of the above events occurred in the year leading up to assessment. |
n = 157,220 142,008: unexposed 15,212: exposed |
| Stressor-induced depression | Binary indicator of whether period of depressed mood or anhedonia was a possible consequence of a traumatic event among individuals endorsing lifetime incidence of a two+ week period characterized by anhedonia and/or depressed mood (questionnaire skip patterns necessitated this precondition). Assessed in the UKBB online mental health follow-up questionnaire. |
n = 88,585 23,746: unrelated to stressor 64,839: stressor-induced |
| Townsend deprivation index (TDI) | Measure of socioeconomic adversity (65), with higher values indicating greater adversity. Standardized to have zero mean and unit standard deviation. Assessed during the UKBB initial touchscreen interview. | n = 187,094 |
†
Depression phenotypes are described in further detail in supplement section S3.1 and visually summarized in Figure S3.1.
‡
Moderator phenotypes are described in further detail in supplement section S3.2 and visually summarized in Figure S3.2. All moderators were only measured in the UKBB.