Agoraphobia (from Greek ἀγορά, "marketplace"; and φόβος/φοβία, -phobia) is an anxiety disorder characterized by anxiety in situations where it is perceived to be difficult or embarrassing to escape. These situations can include, but are not limited to, wide-open spaces, crowds, and uncontrollable social situations such as may be met in shopping malls, airports, and on bridges. Agorophobia is defined within the DSM-IV TR as a subset of panic disorder, involving the fear of incurring a panic attack in those environments. The sufferer may go to great lengths to avoid those situations, in severe cases becoming unable to leave their home or safe haven.
Although mostly thought to be a fear of public places, it is now believed that agoraphobia develops as a complication of panic attacks. However, there is evidence that the implied one-way causal relationship between spontaneous panic attacks and agoraphobia in DSM-IV may be incorrect. Onset is usually between ages 20 and 40 years and more common in women. Approximately 3.2 million, or about 2.2%, of adults in the US between the ages of 18 and 54, suffer from agoraphobia. Agoraphobia can account for approximately 60% of phobias. Studies have shown two different age groups at first onset: early to mid twenties, and early thirties.
In response to a traumatic event, anxiety may interrupt the formation of memories and disrupt the learning processes, resulting in dissociation. Depersonalization (a feeling of disconnection from one’s self) and derealisation (a feeling of disconnection from one's surroundings) are other dissociative methods of withdrawing from anxiety.
Standardized tools such as Panic and Agoraphobia Scale can be used to measure agoraphobia and panic attacks severity and monitoring treatment.