What is an anxiety disorder?

What causes anxiety disorders?

Page last updated: May 2007

There are many interrelated factors associated with anxiety disorders. The causes of a particular disorder vary, and it is not always easy to determine a cause in every case.

Genetic factors

It is well established that the tendency to develop anxiety disorders runs in families. This is similar to a predisposition to other illnesses, such as diabetes and heart disease.

People may also learn anxious responses from parents or other family members.

Biochemical factors

Some anxiety disorders may be related, in part, to a chemical imbalance in the brain. The neurotransmitter that regulates feelings and physical reactions may be involved.


People with certain temperaments are more prone to anxiety disorders.

People who are easily aroused and upset, and are very sensitive and emotional, are more likely to develop anxiety disorders.

People who as children were inhibited and shy may be prone to develop certain anxiety disorders, such as social phobia.

Learnt response

Some people exposed to situations, people or objects that are upsetting or anxiety-arousing may develop an anxiety response. This response can be re-activated when faced with or thinking about the situation, person, or object again.


Stressful life experiences are associated with the development of some anxiety disorders, particularly post traumatic stress disorder.