Researchers analysing data from the UK Biobank have reported that poorer visual acuity was associated with depressive symptoms, measured by Patient Health Questionnaire (PHQ) scores across the full acuity spectrum. Further, poorer visual acuity appeared to be exacerbated the linear associations between the PHQ score and extracellular water diffusion in the fornix (cres) and/or stria terminalis, potentially “indicating deterioration in brain structures with greater depressive symptoms”. In their conclusions, the researchers suggested that visual health was associated with depression in middle aged and older individuals. While vision loss and depression are common conditions with major health implications, public policy supports underline the associations from a large cohort of respondents.
The UK Biobank Study cohort comprised 114,583 volunteers included at baseline from March to June 2006 to July 2010. Visual acuity was examined using the logarithm of the minimum angle of resolution (LogMAR) and depression was measured on PHQ, or through an interview-based psychiatric diagnosis. A sub-group of participants completed multimodal magnetic resonance imaging (MRI) of the brain and PHQ evaluation during the imaging visit from T1-weighted and diffusion MRI. From the results, 62,401 (54.5%) were women and the mean (SD) age was 56.8 (8.1) years (range, 39-72 years). The researchers reported that a 1-line worse visual acuity (0.1 LogMAR increase) was associated with 5% higher odds of depression (odds ratio, 1.05 [95%CI, 1.04-1.07]) after adjustment for age, sex, race and ethnicity, Townsend index, educational qualifications, smoking, alcohol consumption, obesity, physical activity, history of hypertension, diabetes, hyperlipidemia, and family history of depression. In terms of MRI analysis, there were linear associations between PHQ score and the left volume of gray matter in supracalcarine cortex (coefficient, 7.61 [95%CI, 3.90-11.31]) and mean isotropic volume fraction (ISOVF) in the right fornix (cres) and/or stria terminalis (coefficient, 0.003 [95%CI, 0.001-0.004]) after correction for multiple comparison.
In particular data, researchers found that “participants with visual impairment were more likely to be older (mean [SD] age, 58.8 [7.5] vs 56.7 [8.1] years), to be from a racial or ethnic minority group (614 [16.7%] vs 11 659 [10.5%]), to have lower socioeconomic (mean [SD] Townsend index (a measure of material deprivation within a population), −0.18 [3.32] vs −0.98 [2.99]) and educational status (2702 [73.7%] vs 72 038 [64.9%]), to use alcohol less (3336 [91.0%] vs 105 001 [94.8%]), and to not have hyperlipidemia (2098 [57.2%] vs 64 785 [58.4%]). However, participants with visual impairment had higher rates of obesity (963 [26.3%] vs 26 958 [24.3%]), diabetes (329 [9.0%] vs 7228 [6.5%]), and hypertension (2898 [79.0%] vs 82 269 [74.2%]). In the analysis stratified by depression, depression was also associated with a range of health and lifestyle covariates”. Commenting on this comprehensive study, the researchers stated that, “[f]rom a health policy perspective, finding ways to prevent depression and improve daily functioning has substantial public health impacts. Our findings highlight the value of visual health in association with mental health. Screening of vision at an early stage should be embedded in the middle-aged and older population to stratify the vulnerable population at risk for depression”.