Chronic pain — pain that lasts longer than three months — debilitates over 100 million Americans and costs the United States over half a trillion dollars annually, but we still don’t really understand its underlying risk factors.
According to a new study recently published in PLOS Medicine, genetics and your home environment substantially contribute to your risk of chronic pain. The study also found that chronic pain is correlated with major depressive disorder (MDD), and both conditions are in part caused by a variety of genes.
The study was conducted by Andrew McIntosh, MD, chair of biological psychiatry at the University of Edinburgh, and his colleagues using data from two large United Kingdom population studies — including 23,960 individuals from the Generation Scotland: Scottish Family Health Study and 112,151 individuals with genotyping and phenotypic data from the United Kingdom Biobank.
It makes sense that someone with chronic pain has a higher risk of being severely depressed. But the study found that you also have increased risk for major depression if you’re living with a spouse or partner with chronic pain.
The authors discuss possible reasons for this spousal effect, which were summarized in a recent news story:
- “You may choose a spouse similar to yourself, with similar existing predispositions to the conditions (assortative mating).
- It’s possible that caring for a spouse with chronic illness makes you more likely to develop depression.
- The environment you share with your spouse may contribute to both your risks of chronic pain and MDD; shared environmental factors could include diet, infectious disease, and hobbies.”
Determining the extent of these environmental factors was beyond the scope of the current study, but the authors recommend future research to identify the causal mechanisms that link chronic pain and major depressive disorder. They concluded in the paper:
“The answers to these questions are likely to signpost new directions for therapeutic interventions and highlight the symptoms that are most amenable to treatment, as well as prevention.”
This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.