Research Findings on the Genetics of Phobias

A Look at a Review Article on Genetic Causes for Phobias

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Getty Images/Henrik Sorensen

What Are Phobias?

Phobias are extreme fears that make it impossible to function normally. Phobias may grow out of real negative experiences, but because they are overwhelming and often irrational, they become disabling. There are many different types of phobias; some of the most common include:

  • Fear of specific animals (dogs, spiders, etc.)
  • Fear of open spaces, enclosed space, or high places
  • Fear of natural events, such as thunderstorms

    While fears are an unavoidable part of being human, most fears can be controlled and managed. Phobias, however, cause psychological and physical reactions that are difficult if not impossible to manage. As a result, people with phobias will go to great lengths to avoid the object of their fears.

    What Causes Phobias?

    Why someone react to a normal, everyday event -- the bark of a dog, for example -- with extreme fear and anxiety?  Why do other people react to the same experience with mild anxiety or calm?

    The causes of phobias are not yet widely understood. Increasingly, however, research shows that genetics may play at least some role. Studies show that twins who are raised separately have a higher than average rate of developing similar phobias. Other studies show that some phobias run in families, with first-degree relatives of phobia sufferers more likely to develop a phobia.

    In “Untangling genetic networks of panic, phobia, fear and anxiety,” Villafuerte and Burmeister reviewed several earlier studies in an attempt to determine what, if any, genetic causes can be identified for anxiety disorders.

    Family Studies Suggest a Genetic Link

    The researchers found that first-degree relatives of someone suffering from a phobia are approximately three times more likely to develop a phobia. In general, relatives of someone with a specific anxiety disorder are most likely to develop the same disorder. In the case of agoraphobia (fear of open spaces), however, first-degree relatives are also at increased risk for panic disorder, indicating a possible genetic link between agoraphobia and panic disorder.

    According to the findings, twin studies showed that when one twin has agoraphobia, the second twin has a 39% chance of developing the same phobia. When one twin has a specific phobia, the second twin has a 30% chance of also developing a specific phobia. This is much higher than the 10% chance of developing an anxiety disorder found in the general population.

    Gene Isolation Suggests a Link Between Phobias and Panic Disorder

    Although they were unable to specifically isolate the genetic causes of phobias, Villafuerte and Burmeister reviewed several studies that appear to demonstrate genetic anomalies in both mice and humans with anxiety disorders. The early research appears to show that agoraphobia is more closely linked to panic disorder than to the other phobias, but is far from conclusive.

    Conclusion

    More research will need to be performed in order to isolate the complex genetics involved in the development of phobias and other anxiety disorders. However, this study does support the theory that genetics play a major role.

    Source:

    Villafuerte, Sandra and Burmeister, Margit. Untangling genetic networks of panic, phobia, fear and anxiety. Genome Biology. July 28, 2003. 4(8):224. February 19, 2008.

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