Unlike the flu — which you can come down with suddenly after being exposed to the virus — anxiety disorders develop over time due to a number of factors. About 40 million Americans have anxiety disorders, and yet there’s a lot we still don’t know about the causes. Identifying the source of anxiety is not as simple as pointing to a strain of flu virus — the causes of anxiety disorders can be complicated. Here’s what we do know.

Biological and Hereditary Factors

According to the Anxiety and Depression Association of America, researchers are learning that anxiety disorders tend to run in families and have a biological basis, like allergies, diabetes, or heart conditions. If someone in your family has an anxiety disorder, you have a greater risk of developing one too. Your risk is especially high if you have a parent with anxiety.

A study published in the journal PloS ONE, suggests a specific gene — RBFOX1 — may be involved in the development of anxiety-related conditions, such as generalized anxiety disorder. The authors believe that both genetic and nongenetic factors play a part (an anxious parent, for example, will also model anxious behavior, which children pick up on).

Brain chemistry

Parts of the brain that interpret signs of danger, control fear, or the fight-or-flight response can also play a part in anxiety. The amygdala — a small structure located deep inside your brain — processes threat, and alerts the rest of your brain when there are signs of danger. It can trigger fear and anxiety responses, and can be overactive. The amygdala seems to play a part in anxiety disorders that involve fear of specific things — phobias of snakes, elevators, or drowning, for example.

The hippocampus — a region of the brain involved in memory storage of threatening events — may also play a part in your risk of developing an anxiety disorder. In those who have experienced child abuse or served in combat, for example, the hippocampus is smaller in size.


Research suggests that people with certain personality traits are more apt to develop anxiety. Children who are perfectionists, are easily flustered, who have low self-esteem, are timid, or have control issues, sometimes develop anxiety during any stage in their life. Busy, high-strung people — the sort we tend to call “type A personalities” — also have a greater risk of developing an anxiety disorder.

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Life Events

Everyone experiences stress, but chronic stress can lead to long-term anxiety. There are some common but highly stressful life circumstances that can lead to anxiety; work stress, changing jobs, financial trouble, pregnancy and giving birth, family and relationship challenges, and the death or loss of a loved one.

Stress can also lead to behaviors like skipping meals, drinking alcohol, or not getting enough sleep — all of which can trigger or exacerbate anxiety.

Trauma, such as child abuse or military combat, increase your risk of developing anxiety. This can include being the victim of trauma, being close to someone who’s the victim of trauma, or witnessing something traumatic. The major emotional shock following a traumatic event, as well as verbal, sexual, physical, or emotional abuse can all contribute to anxiety disorders.

Other risk factors

There are some chronic illnesses associated with anxiety conditions. Diabetes, asthma, hypertension, heart disease, and irritable bowel syndrome are all correlated with anxiety disorders.

Some experience having an anxiety disorder on its own, while others experience anxiety disorders as part of a fleet of other mental health conditions. Depression and anxiety, for example, often occur together. There’s also a good chance that if you have one anxiety disorder, you will have another.

Alcohol and drug use may also be a risk factor for an anxiety disorder. People often use these substances to control their anxiety symptoms, yet drugs and alcohol can actually exacerbate anxiety conditions as the effects of the drugs wear off.

Lastly, sex plays a part. Women are twice as likely as men to experience anxiety disorders. This could be due to the difference in brain chemistry or hormones between men and women. Another theory is that women generally tend to dwell on their stressors, while many men will opt for a more problem-solving approach. There is also a link that suggests that women are more likely to experience mental and physical abuse — which has been tied to PTSD-induced anxiety.