Depression and anxiety are pervasive global health issues, impacting millions of adults annually. These mental health conditions often coexist, with patients frequently experiencing both simultaneously.
These conditions extend beyond mere sadness. Individuals may feel hopeless, isolated, and lose interest in activities they once enjoyed. These feelings, which can significantly disrupt daily life, are enduring. On the other hand, experts characterize anxiety by persistent, escalating fears that can also interfere with daily activities and personal interactions across various settings, such as home, work, and school.
Depression and anxiety can affect anyone, at any stage of life. While the precise causes remain elusive, experts generally agree that a combination of genetic and environmental factors plays a role. The risk may be heightened for individuals with a family history of these disorders. They are also common for those who have experienced traumatic events, or those who consume certain medications, drugs, or alcohol.
The primary treatment for these conditions typically involves therapy and medication. Talk therapy is often the first line of defense. In cases of severe depression or anxiety, doctors may prescribe antidepressants or anti-anxiety medications. It can take several weeks for these medications to take effect, and finding the right combination and dosage can be a process of trial and error.
Affect on an Aging Population
While depression and anxiety can affect individuals of all ages, these conditions are particularly prevalent among the elderly. Researchers have explored whether poor mental health accelerates biological aging, which refers to the body’s age at the molecular level, independent of chronological age. However, less attention has been paid to the reverse question: Does biological aging increase the risk of depression and anxiety?
A recent study published in Nature Communications sought to address this question. The researchers estimated biological age based on DNA methylation profiles from blood samples and evaluated the mental health of a large cohort of study participants. They discovered that participants with an increased biological age relative to the chronological age had a 6-11% increased risk of developing depression and anxiety over approximately nine years.
| This post may interest those with a higher polygenic risk score for anxiety and depression. |
The Study
The study involved over 424,000 participants from the UK Biobank. The researchers collected lifestyle and health information (including self-reported mental health) and blood samples for biological age measurements. The authors followed up with study participants nine years later to collect a second set of mental health measurements. The cohort was predominantly white, with a roughly equal gender split and a median age of 57.
Results
The researchers found that participants whose biological age was increased relative to the chronological age were at a higher risk for anxiety and depression. Even when they accounted for socioeconomic factors, health behaviors, and chronic diseases (such as diabetes, cardiovascular disease, or cancer), the association remained significant, albeit slightly reduced.
The researchers also examined the role of genetics. They found that participants with a higher polygenic risk score (calculated from two genome-wide association studies) had lower mental health states at the beginning of the study and a greater risk of developing depression or anxiety in the future. However, this polygenic score was not correlated with an older biological age, suggesting that these two variables (genetics and biological age) operate independently and may be additive factors.
Summary
The study’s findings suggest that being biologically older may be a risk factor for depression and anxiety in older adults. This connection implies that interventions targeting biological aging could potentially prevent the late-life onset of these mental disorders.
The researchers acknowledge that their study does not explore the mechanisms through which biological aging contributes to the risk of mental health disorders. They propose that molecular changes, such as telomere shortening, might directly impact the psychological processes that trigger anxiety and depression. Other downstream effects, like changes in the brain and deteriorating physical health, might also play a role.
One limitation of this study is its observational nature, which may overlook unobserved variables that contribute to biological age and the development of mental health disorders. Additionally, the UK Biobank’s demographic tends to be middle-aged, White, and of higher socioeconomic status. The follow-up evaluation, which included about one-third of the initial participants, may have been biased due to those factors.
Citation
Gao X, Geng T, Jiang M, Huang N, Zheng Y, Belsky DW, Huang T. Accelerated biological aging and risk of depression and anxiety: evidence from 424,299 UK Biobank participants. Nat Commun. 2023 Apr 20;14(1):2277. doi: 10.1038/s41467-023-38013-7. PMID: 37080981; PMCID: PMC10119095.
