What are the Causes of Panic Disorder?

Panic disorder, characterized by debilitating and reoccurring panic attacks, has no known single cause. Etiology of the disorder shows that genetic predisposition and socio-economic environment are factors in determining who is susceptible. Therefore, a person who has a close family member with the disorder has a significantly higher risk of developing it. The physiologic symptoms of panic disorder are caused, in part, by low levels of serotonin in the brain and an overactive sympathetic nervous system response. The onset of panic disorder is caused by panic attacks becoming closer and closer together, with the person experiencing them beginning to show anticipatory fear of the actual panic attack and not just fear of the trigger.

Repeated panic attacks lead to the body being in an almost constant state of arousal caused by the "fight or flight" response, a human adaptation that arose in response to physical danger in the environment. This response is triggered by an event that the brain perceives as dangerous; nerves in the autonomic nervous system (ANS) initiate adrenal release from glands in the kidneys, and the kidneys pump adrenaline and noradrenalin throughout the body. These chemicals raise the heart rate and blood pressure in order to get more oxygen to the muscles needed to either run from or physically attack the perceived danger.

In a person without panic disorder, after the danger has passed, the parasympathetic nervous system initiates a series of biochemical events to bring the body back to a state of homeostasis. When the sympathetic system is stimulated by the panic response too often, it may not be able to effectively shut down with the help of the parasympathetic nervous system, which can also develop dysfunction related to the causes of panic disorder. Decreased oxygen supply to the brain causes dizziness and feelings of unreality that are associated symptoms, as well as other symptoms of oxygen deprivation like cold and clammy extremities. The body's reaction to the trigger forces it to focus entirely on the perceived fight at hand, and the person suffering from panic disorder may have problems with memory, cognition, and attention.

Genetic variations may be a factor in the serotonin aspect of the causes of panic disorder. Research shows that just as patients can be predisposed to develop major depression because of lack of the genetic code to create adequate receptors, the same holds true for individuals with panic disorders. For this reason, doctors have success treating the causes of panic disorder with selective serotonin reuptake inhibitors (SSRIs) and similar drugs. Benzodiazepines can be used to treat acute panic, and cognitive behavioral therapy (CBT) is generally recommended to effectively treat the whole spectrum of the causes of panic disorder.