A recent study found that worsened visual acuity and depression were associated with neurobiological changes visible through MRI scans.
Research suggests that depressive symptoms in older adults were associated with poor visual acuity, and that visual health was associated with altered brain neurobiology.
One of the primary contributors to diminished health and well-being of older populations is known to be visual health decline. Visual impairment is known to play a major role in depression for older adults, potentially due to its effects on vision, mobility, and even risk of poverty.
This study sought out to analyze the associations between depressive symptoms and visual health in middle-aged and older adults within the United Kingdom. The research was led by Xiayin Zhang, PhD, and Honghua Yu, PhD, of the Guangdong Eye Institute in Guangdong Provincial People’s Hospital’s Department of Ophthalmology.
“From a health policy perspective, finding ways to prevent depression and improve daily functioning has substantial public health impacts,” Zhang and colleagues wrote. “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.”
The investigators used a cohort study, with a sample of 114,583 older adult participants from the UK Biobank database. The volunteers were included at baseline from March through June 2006 up until July 2010. They found that about 55% (62,401) of participants were female and about 46% (52,182) were male. The participants’ mean age was about 56.8 years.
The research team also analyzed participants’ demographic information and covariates such as obesity, alcohol use, physical activity, and genetic history of depression. Depression scores for participants were assessed through either an interview-based diagnosis from a psychiatrist or through the Patient Health Questionnaire (PHQ).
The investigators also analyzed multimodal magnetic resonance imaging (MRI) brain scans of a subgroup of 7844 eligible participants. Participants with brain-damaging diseases such as Parkinson’s or strokes were excluded from the study. They analyzed the research data from May 5 to August 9, 2022.
The investigators found that a 1-line worse visual acuity was associated with 5% higher chance of depressive symptoms (odds ratio, 1.05 [95% CI, 1.04 - 1.07]). This statistic was found after adjusting for demographic characteristics, Townsend index, education, alcohol and tobacco consumption, obesity, physical exercise, hyperlipidemia, hypertension history, diabetes, and familial history of depression.
In the subgroup recruited to receive MRI scans, the investigators found that there were linear associations between PHQ scores and extracellular water diffusion in the fornix of the brain and/or the stria terminalis. They also found linear associations between the participants’ PHQ scores and the left volume of gray matter in supracalcarine cortex
Participants’ levels of visual acuity could moderate these associations, as higher PHQ scores were associated with higher isotropic volume fraction (ISOVF) levels only with participants with diminished visual acuity.
“Studies on mental health supported our hypothesis that the fornix and stria terminalis are involved in the pathophysiology of schizophrenia, bipolar disorder, and autism spectrum disorder,” they wrote.”Thus, our findings suggest that poorer visual acuity was associated with greater depressive symptoms and may have contributed to the related deterioration of the fornix and stria terminalis.”
This study, “Association of Visual Health With Depressive Symptoms and Brain Imaging Phenotypes Among Middle-Aged and Older Adults,” was published online on JAMA Network Open.