More than 15 million Americans are currently living with depression in the United States, the Anxiety and Depression Association of America reports, and depression can develop at any age. While it’s not uncommon to feel sad every once in a while, clinical depression is a constant feeling, and it’s important to know the difference between sadness and a debilitating mental illness. There are silent signs of depression, including hiding your feelings and randomly feeling mad, but research is pointing to a possible new indicator for depression—your genes.
In a study published by Rosanna Scott in The Journal of Clinical Psychiatry, researchers found that there’s a possible gene variant in the DNA of nearly 25 percent of the population that can increase your risk of developing depression. Science Daily reports that people with the gene variant, polipoprotein-E4 (ApoE4 for short), have an increased chance of developing clinically significant depressive symptoms later in life compared to those who don’t have the gene variant.
For the study, Dr. Scott used data from more than 3,000 participants aged 53 to 71, who were part of the Wisconsin Longitudinal Study, a long-term study of health, relationships, mortality, among people who graduated from Wisconsin high schools in 1957. Based on the data, Dr. Scott found that those with ApoE4 noted more symptoms of depression as they grew older.
According to Dr. Scott’s co-author, Daniel Paulson, this gene can be an indicator of future depression development, but it doesn’t necessarily mean you’ll definitely develop depression. “Some genes are deterministic, like the one that causes Huntington’s disease—where if you’ve got it, you’ll get the disease. This isn’t one of those genes,” he said.
This isn’t the first time that Dr. Scott has looked at the effects of the ApoE4 gene. Her previous research looked at the negative impact of the gene on how our body handles high cholesterol, and served as the inspiration for this study. She wanted to see if adults with ApoE4 and high vascular burden were at a compounded risk for depression. Based on her research, she was able to conclude that ApoE4 and poor vascular health do not create a compounded risk, but both separately increase the chance of depression.
“Bottom line, you do statistically have a higher risk of developing depression if you have ApoE4, but it’s not fate. You can’t change your genes, but you do have some control over improving your health,” Dr. Scott said. “That should be encouraging.”