Is anxiety genetic? About a third of it, and here is what that means

If your mother is a worrier and her mother was too, it is natural to wonder whether you inherited it along with the eye color. The short answer is: partly. The part that is not inherited is bigger than most people expect, and the inherited part does not work the way the word "gene" makes it sound.

How we know it runs in families, and that it is not only upbringing

Family studies came first. Having a parent or sibling with an anxiety disorder raises your own odds about four- to six-fold. That could be genes, or it could be a household. Twins settle it: identical twins share all their DNA, fraternal twins half. If identical twins match more often, genes are at work.

When researchers pooled the twin studies in 2001, generalized anxiety came out at 32 percent heritable and panic disorder at 43 percent. One detail from that analysis is easy to miss: most of the remaining variance was "nonshared environment". Not the family you grew up in, which siblings share, but the experiences that happened to you alone.

A word on what "32 percent heritable" means, because it is often misread. It does not mean a third of your anxiety is genetic. It means that across a population, about a third of the differences between people trace back to differences in their DNA. For any one person the split is unknowable.

What the DNA studies found

Twin studies say genes matter; DNA studies try to find which ones. In 2020 a study of 83,000 people, 25,453 of them with a lifetime anxiety disorder, found five spots in the genome tied to anxiety. One sits in NTRK2, the gene for the receptor that BDNF, a brain growth factor, plugs into. Added together, common variants explained 26 percent of the risk, close to the twin number. The twin studies were right; the signal is simply spread very thin.

How thin: a study of 329,821 people looking at neuroticism, the worry-prone personality trait, found 116 separate spots. Each one shifts the trait by a hair. Add every known spot into a score and it still explains only a few percent of the differences between people. That is why a DNA report that calls you "anxious" or "calm" from a handful of markers is reading tea leaves.

The famous anxiety genes mostly did not hold up

You may have seen COMT, the "warrior or worrier" gene. The idea was that the slow version leaves more dopamine in the front of the brain, making people more sensitive and more anxious. When 27 studies with 15,979 people were pooled, the picture fell apart: no association in women at all, and in white men the direction was reversed, with the fast version slightly more neurotic. Small, inconsistent, population-specific. We wrote about COMT separately. Treat your result as an interesting fact, not a label.

The other two thirds

That is where the useful news is. The bigger share of what makes one person more anxious than another is not inherited, and much of it is within reach: sleep, caffeine, alcohol, how much of the day is spent under load, whether there is anyone to talk to. Caffeine is a good example. Some people feel jittery after one cup, and a marker in ADORA2A, the receptor caffeine blocks, leans that way. But the dose and the habit matter far more than the marker, and cutting the afternoon coffee changes an evening in a way no gene can.

If anxiety is getting in the way of your life, that is a conversation for a clinician, and it is something they help with every day. A DNA file is not where that answer lives.

What a DNA file can honestly say

Leanings, sized honestly. Whether you tend to feel caffeine as jitters. Which way your dopamine-clearing enzyme runs. Whether your common markers for worry-proneness point slightly up or slightly down. None of it is a verdict, and the report says so on every card, in plain words.

Sources

1. Hettema JM, Neale MC, Kendler KS. A review and meta-analysis of the genetic epidemiology of anxiety disorders. American Journal of Psychiatry, 2001. PubMed 11578982
2. Purves KL, Coleman JRI, Meier SM, et al. A major role for common genetic variation in anxiety disorders. Molecular Psychiatry, 2020. PubMed 31748690
3. Luciano M, Hagenaars SP, Davies G, et al. Association analysis in over 329,000 individuals identifies 116 independent variants influencing neuroticism. Nature Genetics, 2018. PubMed 29255261
4. Lee LO, Prescott CA. Association of the catechol-O-methyltransferase val158met polymorphism and anxiety-related traits: a meta-analysis. Psychiatric Genetics, 2014. PubMed 24300663