To be self-aware and future-thinking is to be anxious. Human beings are finite creatures. We know the end is coming, we just don’t know for sure how or when. For the most part, we have adapted to put that out of our minds and pretend that our present behaviour is not tied to our ultimate outcome.

I volunteer at a senior living community one day a week, in part to see how people deal with end-of-life issues. Nearly all the people living there believe it will be their last home; there is no illusion that the next stop on life’s journey will not be the last stop. Their attitudes, however, are about as evenly distributed as in high school: some optimists, some pessimists, and most just go with the flow.

There is a genetic component to anxiety, but not much. An article on the genetics of anxiety disorders in the journal Current Psychiatric Reports finds the condition is “moderately heritable.” A clever way to tease out the genetic component to anxiety disorders used the famous Swedish Twin Registry.

Researchers from Germany, Sweden and Denmark found 2,515 individuals in the registry who had been prescribed anxiety medications. They felt they could determine the contribution of genetics to anxiety by comparing the rates at which twins responded to medication.

The researchers compared the polygenic risk scores (PRSs) to predict the patient’s response to “antidepressants, benzodiazepines, and antihistamines for anxiety and depression.” They found that:

PRSs related to depression, anxiety, and schizophrenia predicted responses to benzodiazepines and antihistamines but not antidepressants.

The details are a bit more nuanced. First off, “None of the investigated PRSs significantly predicted monotherapy with antidepressants.” For patients with depression prescribed benzodiazepines, there is a correlation between PRS and response to medication. For patients with schizophrenia and “lifetime anxiety disorder,” there is a correlation between the response to medication and PRS. The odds ratio is roughly 1.25. If a score of 1 is no correlation and a score of 2 is perfect correlation, one might surmise that PRSs predict about 25% of anxiety disorders.

One study went so far as to say that “several of the same genes linked to canine behavior are also tied to human traits like anxiety, depression, and intelligence.” So perhaps anxious people are Jack Russells and chill people are Black Labs?

Where does the rest of the anxiety come from? First and foremost, epigenetics: genes that are turned on or off during pregnancy and early life. An article in the journal Pharmacology Biochemistry & Behavior states that:

The human literature is in its infancy but does reveal some epigenetic associations with anxiety behaviors and disorders.

Most of the research has been done on animals. “Using animal models of anxiety,” the authors note, “researchers have identified epigenetic changes in several limbic and cortical brain regions known to be involved in stress and emotion responses.” Not only do they find that stress, toxins, and diet can result in epigenetic changes associated with a predisposition towards anxiety, but these changes are heritable and can be passed down.

Now we have about a quarter of anxiety disorders predicted by genetics, and another big chunk the result of epigenetic trauma, then we add the stressors of being alive, obtaining food, water, shelter, and security, and making a living, and you arrive at 100% anxiety and the beginning of substance use disorders and compulsive behaviors.

Substance abuse disorders and anxiety disorders have a “high prevalence” of co-occurrence and comorbidity, say the authors of a review in Psychiatric Times. Anxiety turns into disorders through the process of displacement. As stress and anxiety build, the need to displace the tension results in a search for dopamine to calm the nerves.

For many addicts, the craving for that dopamine rush becomes a source of anxiety itself, fueling a vicious cycle in which the cure exacerbates the problem. This is the box addiction creates. One way out of the box is medication. Drugs such as buprenorphine can reduce the cravings of withdrawal, and GLP-1 drugs can reduce the desire to consume, but the conditions will persist if the underlying sources of anxiety are not resolved.

To be human is to be anxious. That anxiety must be managed to keep it below a level that triggers displacement into potentially harmful actions and stupid decisions. The best strategies for reducing stress start young and involve not inducing traumas that cause lifelong fears. We need to teach stress reduction and calming skills early in life and strengthen them with exercise, yoga, and creative pursuits.

It turns out that the ability to keep a lid on things might not be genetic and might need to be taught and used in order to mitigate the stresses of everyday life.

Written by Steve O’Keefe. First published March 16, 2026.

Sources:

“Genetics of Anxiety Disorders,” Current Psychiatric Reports, March 2, 2019.

“Association Between Polygenic Risk Scores and Treatment Response to Antidepressants, Benzodiazepines, and Antihistamines in Anxiety and Depression,” Biological Psychiatry: Global Open Science, February 18, 2025.

Don’t worry; be informed about the epigenetics of anxiety,” Pharmacology Biochemistry & Behavior, May 14, 2016.

“Anxiety and Substance Use Disorders: A Review,” Psychiatric Times, July 16, 2010.

“Golden Retriever genes linked to anxiety, aggression, and intelligence in humans,” ScienceDaily, March 7, 2026.

“The Logic of Anxiety,” Vox, March 9, 2026.

Image Copyright: mrwed54.