If you've ever dealt with both anxiety and depression, you know they can feel intertwined. This study looked at whether the genetic risks for each disorder are different when they appear alone versus together. Researchers analyzed genetic data from large UK and Norwegian cohorts, focusing on people with anxiety only, depression only, or both.
They found that genetic risk scores for depression were more strongly linked to people with both conditions than to those with depression alone. Similarly, genetic risk for anxiety was more strongly tied to the comorbid group. The genetic overlap between anxiety and depression was much higher when both disorders were present than when they occurred separately. Mendelian randomization suggested that causal effects between the disorders faded when comorbid cases were excluded.
The study also noted that immune-related genes were more active in people with depression, whether alone or with anxiety, but not in those with anxiety alone. However, this is an observational study, so it can't prove that genes cause these disorders. The results are based on statistical associations and early genetic clues, not definitive answers.