Agoraphobia

Etiology

Agoraphobia is usually first identified in young adults, with the mean age of diagnosis beginning in the mid to late twenties. There is no consensus on the childhood experiences, personality characteristics, or psychosocial risk factors that lead to a diagnosis of agoraphobia. However, proposals point to several commonly occurring etiological factors. These include parental overprotectiveness, the presence of childhood fears or night terrors, experience of grief or bereavement early in life, unhappy or traumatic childhoods, or genetic predisposition. Comorbid personality types include dependent, obsessive-compulsive, or otherwise “highly-neurotic.”[3]

The DSM-5 further stratifies risk factors into three categories: temperamental (neuroticism, sensitivity to anxiety, and anxiety disorders), environmental (negative or traumatic events in childhood, and reduced warmth or overprotectiveness in childhood), and genetic and physiological predisposition.

Epidemiology

Anxiety disorders, encompassing generalized anxiety disorder, panic disorder, and agoraphobia, are highly prevalent in the general population.[1] There is some disparity in estimates for the prevalence of agoraphobia as it has only recently received its own diagnostic criteria rather than as a qualifier for panic disorder. According to the DSM-5, agoraphobia is present in approximately 1.7% of the general population. It further states that most cases of agoraphobia present before the age of 35. There is an increase in the risk of developing agoraphobia in late adolescence and early adulthood, with the overall average age at onset being 17 years. The National Institute of Mental Health estimates that the lifetime prevalence of agoraphobia is 1.3%, with an annual incidence rate of 0.9%. Yearly prevalence rates of agoraphobia are similar between males (0.8%) and females (0.9%).

History and Physical

As with all psychiatric diagnoses, an essential tool in diagnosis is the interview. There is no physical exam finding that would indicate a diagnosis of agoraphobia.

Evaluation

The DSM-5 outlines the criteria by which a diagnosis of agoraphobia is possible.[2] To definitively diagnose a patient with agoraphobia, they must have intense fear in response to or when anticipating entering into at least two of the five following situations: using public transportation (automobiles, buses, trains), being in open spaces (marketplaces, parking lots), being in enclosed spaces like theaters or malls, standing in lines or crowds, or being outside of the home alone. This fear, which is out of proportion to the actual stimulus, must be accompanied by behavioral or cognitive modifications to avoid placing oneself in situations where the exposure may occur. These symptoms must be present for at least six months and must cause significant distress to the patient and impairment in their lives. The symptoms also should not be better explained by another psychiatric diagnosis, be directly caused by a medical diagnosis, or occur in the context of substance use or withdrawal.

Treatment / Management

Though panic disorder and agoraphobia have been differentiated, with two different sets of diagnostic criteria, the treatment algorithms for the two remain similar. The first step is to identify the severity of the disease when the patient presents; this is often a measure of the level of impairment or distress the agoraphobia or panic disorder causes in the patient’s life.

Patients with mild or moderate panic disorder or agoraphobia can choose between psychotherapy and pharmacotherapy to achieve adequate symptom management. Studies have generally concluded that cognitive-behavioral therapy (CBT) effectively addresses and alleviates target symptoms, lessens other anxiety symptoms, and improves the patient's quality of life.[4] For patients with more severe forms of agoraphobia or for those who prefer pharmacotherapy over psychotherapy, there are several effective options for medication management. Selective serotonin receptor inhibitors (SSRIs) are generally considered first-line therapy, with therapeutic doses being the same as in depression.[5] Serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and benzodiazepines have also been effective alternatives SSRIs in the treatment of panic disorder and agoraphobia.[6][7] SSRIs are generally preferable to these other medications because of the side effect profile, affordability, availability, decreased potential for abuse, and better tolerability.[8][9][10] There is also data suggesting that the combination of CBT with pharmacotherapy may be most effective in the symptomatic management of agoraphobia and panic disorder.[11](A1)

Differential Diagnosis

According to the DSM-5, the most common differential diagnoses for agoraphobia include specific phobia, separation anxiety disorder, social anxiety disorder, panic disorder, acute stress disorder or posttraumatic stress disorder, and major depressive disorder. Specific phobia should be diagnosed, rather than agoraphobia, if the fear, anxiety, avoidance, or behavioral modification is limited to one of the five, rather than two, of the situations in which agoraphobia can occur. Separation anxiety disorder can be differentiated from agoraphobia if the fear or anxiety arises when considering detachment from loved ones or the home environment, rather than the panic associated with being in the feared situations themselves.

Social anxiety involves fear about being negatively judged in public situations rather than, like separation anxiety disorder, being in the situations themselves. Panic disorder is the appropriate diagnosis if the panic symptoms occur in less than two of the five diagnostic agoraphobic conditions or if they occur in other non-public situations or circumstances. Acute stress disorder or posttraumatic stress disorder is the diagnosis if the fear, anxiety, or avoidance functions to avoid reminding the individual of a past traumatic event. Major depressive disorder should be the diagnosis if the patient also reports associated anhedonia, apathy, loss of energy, insomnia, or low self-esteem. Agoraphobia also cannot be diagnosed if the behavioral modifications are to avoid consequences of medical conditions, such as fears of losing consciousness in public for someone with cardiovascular pathology or developing diarrhea in someone with inflammatory bowel disease.

Prognosis

The DSM-5 describes the course of agoraphobia as “persistent and chronic,” with complete remission being relatively rare except with treatment or intervention.[12] Rates of remission are reduced when the severity of agoraphobia is higher. The chance of a favorable prognosis is also reduced by the presence of comorbid anxiety disorders, depression, personality disorders, or substance use disorders.

Complications

Agoraphobia itself is associated with significant distress and impairment in life. In severe cases, it can cause individuals to become completely home-bound and dependent on others for anything that requires leaving one’s home. This can lead to self-medication with non-prescription medications or other substances. The DSM-5 states that remission rates without treatment are quite low, with averages estimated at about 10%.

Agoraphobia is also associated with an increased risk of developing comorbid major depressive disorder, persistent depressive disorder (dysthymia), and substance use disorders.