Depression can certainly take its toll on a variety of physical and mental processes, so it’s no surprise that major depression often coincides with a shortened lifespan. Now scientists are finding that there may be more to this link than just purely an unfortunate coincidence. According to a new study, major depression disorder (MDD) may actually speed up the aging process on a molecular level and the results illuminate a significant epigenetic mechanism.
MDD is a very common mental disorder present in people of all ages. According to the World Health Organization, an estimated 300 million people around the world suffer from depression. Symptoms can include anxiety, guilt, hopelessness, mood swings and in some circumstances can sadly result in suicide. Treatments have made significant improvements over the years, but there’s still a long way to go when it comes to prevention and eradication. Depression affects a person’s quality of life, and may even impact their epigenetic health and age, so it is important to find any help possible.
The role of epigenetics in MDD is not well known, but current research is investigating the changes that MDD can make to a person’s DNA, histones and chromatin. This devastating disease hides behind many faces and can be a product of various things like socio-economic status, PTSD, bipolar disorder, and other factors.
In a study published in The American Journal of Psychiatry, Dr. Laura Han from the Amsterdam UMC led a group of researchers to determine the effects that MDD has on a person’s epigenetic age. Dr. Han and her team focused on the patient’s epigenetic clock, which is a molecular age estimation of most tissues and cell types based on a person’s DNA patterns at a point in their life.
DNA methylation is an epigenetic mechanism involving the addition of methyl groups to regions on a person’s DNA, which can thereby alter the way certain genes are expressed. Previous studies have implied that increased DNA methylation at specific genes may lead to developing MDD.
As we know, changes to a person’s epigenetic clock can severely influence the length of their life, no matter how healthy their lifestyle is. Previous studies have shown that people who suffer from depression or a past trauma may have a shorter lifespan than healthy people due to accelerated epigenetic aging.
To further determine the epigenetic effects of depression, the research team examined blood samples from 811 patients with depression, and 319 control patients, focusing on how DNA changes with age, especially as people enter their 50s and 60s.
The researchers found a significantly higher rate of epigenetic aging in patients with MDD by an average of 8 months when compared to healthy patients.
Patients were also surveyed about a past trauma they may have endured in their childhood like emotional neglect or sexual abuse. Those who had suffered seemed to have experienced a magnified effect—having DNA that was aged about 1.06 years more than the control patients. In some cases, patients with extreme depression exhibited an epigenetic age of 10-15 years older than their actual age.
“What we see is in fact an ‘epigenetic clock’, where the patterns of modification of the body’s DNA is an indicator of biological age. And this clock seems to run faster in those who are currently depressed or have been stressed” said Dr. Han.
The research team then examined the post-mortem brain samples of 74 patients with depression, and 64 healthy brain samples and found similar DNA methylation patterns, further confirming the epigenetic effect on biological age. Dr. Han highlights the importance of their confirmation: “The fact that we saw similar results in both blood samples and post-mortem brain tissue helps support the belief that this is a real effect we are seeing”.
While more research is needed to strengthen the findings of this study, the results are crucial as it signifies the biological effect of trauma and depression on an epigenetic level. It also points out the importance of early preventive and therapeutic measures when it comes to depression and adverse childhood experiences.
Epigenetics research may be in its infancy when it comes to depression, but the discovery of MDD’s effect on DNA methylation offers valuable insight to developing effective treatment and prevention methods to limit the disastrous effect of this disease.
If you or a loved one is struggling with depression, please visit This Way Up for help.
Source: Laura K.M. Han et al. (2018). Epigenetic Aging in Major Depressive Disorder American Journal of Psychiatry, 2018; 175 (8)
Reference: ECNP Press Release Study shows DNA of people with childhood abuse or depression ages faster European College of Neuropsychopharmacology. 7 Oct 2018. Web.