Claustrophobia is a fear of enclosed spaces or physical restriction. It is often present with anxiety disorders. Claustrophobia affects approximately 4 percent of the population.
Common triggers for attacks of claustrophobia include:
- small windowless rooms
- small cars
- MRI or CT scanners
- crowded rooms
- public restrooms
- car washes
- revolving doors
- changing rooms
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The symptoms of claustrophobia can be very dramatic and unpleasant. Common physical reactions include sweating, shaking, nausea, and faintness. Sufferers may also experience lightheadedness, dry mouth, or numbness. In more severe cases, panic attacks are possible.
Perceptions of space
A recent study of how people with claustrophobia perceive the space around them shows that near and far space are significant in the development of the disorder.
Near space and far space are perceived differently by the brain. There are specific neurons that respond to objects that are close to or approaching the body. Most people have a small perception bias toward the left when viewing near space objects. The bias shifts rightward for distant spaces. The rate of shift from left to right as the distance increases can be used as a marker for the perceived size of near space. It was found that people with shorter arms tend to have smaller near spaces, and those with longer arms have larger near spaces.
In the study, however, independently of arm length and other factors, people with high levels of claustrophobia had larger near spaces than those with less. Thus, claustrophobia may derive in part from distortions in the perception of near space.
Claustrophobia can run in families. A single gene encoding a stress-regulated neuronal protein, GPm6a, can cause claustrophobia. In a 2013 study published in Transl. Psychiatry, mice deficient in Gpm6a had no obvious abnormalities, but could be induced to develop claustrophobia. In humans, mutations of the Gpm6a gene were more common in claustrophobic individuals than those without claustrophobia.
The amygdala is the part of the brain that controls anxiety. The size of the amygdala may influence a person’s susceptibility to anxiety disorders, including claustrophobia. In a study comparing the size of amygdala between patients with panic disorder and patients without panic disorder, those with panic disorder had smaller amygdala volumes. They also had smaller hippocampus volumes.
Trauma early in life is thought to be another contributor to claustrophobia. In classical conditioning, a trigger is connected to a response. Claustrophobia can occur when confinement is linked to danger by the brain, becoming a trigger for panic symptoms. For example, a child shut in a dark closet or trapped in a small space may later develop claustrophobia. Claustrophobia is also believed by some to result from a traumatic birth.
The human brain is primed for fears of certain triggers that may be dangerous. Evolution has prepared the brain to recognize dangers in the environment. This “prepared phobia” would be an advantage during evolution, allowing humans to quickly recognize and escape a dangerous situation. Because it is so common, and because confined spaces can be dangerous (e.g. suffocation), prepared phobia may contribute to the development of claustrophobia.