Panic disorder has both biological and psychological causes. Because the disorder runs in families, researchers are examining several genes that might contribute to its development.
Some experiments suggest that panic disorder is the result of a hypersensitivity to brain changes that transmit warning messages. In these experiments, panic attacks were induced in susceptible people with high doses of a stimulant like caffeine, which activates the sympathetic nervous system (a part of the autonomic nervous system). The sympathetic nervous system transmits signals to all parts of the body to prepare it for physical action, known as the "fight-or-flight" response. It speeds heart rate, narrows blood vessels, and raises blood pressure.
In most people, large amounts of caffeine produce some of the physical symptoms of panic, such as increased heart rate. But among individuals with panic disorder, too much caffeine can trigger a full-blown panic attack. In similar experiments, deep breathing caused by strenuous exercise or inhaling air with a high concentration of carbon dioxide provoked attacks in people with panic disorder. The brain seemingly misinterprets deep, rapid breathing as a sign that the body is in trouble and triggers a stress response.
One theory is that faulty brain receptors don't respond to naturally occurring benzodiazepines, the body's anxiety-reducing chemicals. Some research suggests that panic disorder may involve an abnormality in the limbic system. Brain images of people having a panic attack show abnormal activity around the hippocampus, a key component of the limbic system.
Psychological factors are also important because a major symptom is the fear of having more panic attacks. People become conditioned to anticipate the attacks. This anticipation produces anxious thoughts, which may induce panic attacks. Researchers think the amygdala may play a role in anticipatory anxiety and are studying this part of the brain, where fear conditioning and other forms of unconscious emotional learning occur.
Some experiments suggest that panic disorder is the result of a hypersensitivity to brain changes that transmit warning messages. In these experiments, panic attacks were induced in susceptible people with high doses of a stimulant like caffeine, which activates the sympathetic nervous system (a part of the autonomic nervous system). The sympathetic nervous system transmits signals to all parts of the body to prepare it for physical action, known as the "fight-or-flight" response. It speeds heart rate, narrows blood vessels, and raises blood pressure.
In most people, large amounts of caffeine produce some of the physical symptoms of panic, such as increased heart rate. But among individuals with panic disorder, too much caffeine can trigger a full-blown panic attack. In similar experiments, deep breathing caused by strenuous exercise or inhaling air with a high concentration of carbon dioxide provoked attacks in people with panic disorder. The brain seemingly misinterprets deep, rapid breathing as a sign that the body is in trouble and triggers a stress response.
One theory is that faulty brain receptors don't respond to naturally occurring benzodiazepines, the body's anxiety-reducing chemicals. Some research suggests that panic disorder may involve an abnormality in the limbic system. Brain images of people having a panic attack show abnormal activity around the hippocampus, a key component of the limbic system.
Psychological factors are also important because a major symptom is the fear of having more panic attacks. People become conditioned to anticipate the attacks. This anticipation produces anxious thoughts, which may induce panic attacks. Researchers think the amygdala may play a role in anticipatory anxiety and are studying this part of the brain, where fear conditioning and other forms of unconscious emotional learning occur.
