The exact cause of panic disorder is not known. However, several theories suggest the disorder develops based on a complex interaction of biological, genetic, environmental and/or social factors and experiences.
Biological Theories of Panic Disorder
Many experts believe there is a strong biological component in the development and maintenance of panic disorder. The brain contains millions of neurotransmitters, or chemical messengers that communicate with each other. Serotonin, norepinephrine, and gamma-aminobutyric acid (GABA) are chemical messengers that are believed to play an important role in panic disorder. From a biological perspective, one theory of panic disorder is that symptoms are caused by an imbalance of one or more of these chemical messengers.
The Fight-or-Flight Response Theory of Panic Disorder
One theory of the cause of panic disorder is that the body’s alarm system, called the fight-or-flight response, is triggered without cause. The fight-or-flight response is a stress response exhibited by many animals, including humans. It is believed to be an innate and automatic response for survival. Basically, this means that when a threat is perceived, physical and psychological changes occur, getting one ready to flee or engage in battle.
Suffocation False Alarm Theory
There has been considerable research and speculation about the role of carbon dioxide in panic disorder. The suffocation alarm theory holds that when levels of carbon dioxide and oxygen are altered, as occurs during hyperventilation, a message is sent that there is a danger of suffocation. The result of this message is panic. People with panic disorder demonstrate an increased sensitivity to carbon dioxide and oxygen changes in the blood. During anxiety and panic, improper breathing can upset the oxygen and carbon dioxide exchange, resulting in an improper balance of each. The suffocation false alarm theory proposes that a potential suffocation alarm is erroneously triggered as a result of this imbalance and because the alarm system is overly sensitive.
The Genetic Link
Individuals with a first-line (i.e., parent, sibling, grandparent) biological relative with panic disorder are 8 times more likely to develop the condition. If the family history includes first-line relatives who develop the disorder before age 20, the risk is even greater. Studies of identical twins also show a genetic connection. If one identical twin has PD, the other will develop the disorder about 40% of the time.
Environmental Sources
Some researchers have found evidence of certain environmental elements and cues that may contribute to the development of panic disorder. These sources include:
- Parents who are anxious may model this anxious behavior to their children
- Overprotective parenting styles
- Insecure attachment patterns during childhood
- Childhood abuse or trauma
- High levels of stress in the home during upbringing
- Major stressful life events
- Hypersensitivity to certain harmless bodily sensations with the perception they are dangerous
- A temperamental style associated with passiveness and avoidance of new stimuli
Putting it All Together
Here’s an overview of what is known so far about the cause of panic disorder:
- There appears to be a genetic correlation because it does tend to run in families. But, even identical twin studies don’t show a genetic correlation 100% of the time.
- There appears to be some common environmental sources of panic disorder. But, not all people who experience these environmental triggers are affected. Not all people who grow up in homes with anxious parents, or have insecure attachment patterns or high levels of stress, get panic disorder.
- Studies have identified certain metabolic challenges and brain chemical abnormalities in people with panic disorder. But, trying to determine whether anxiety causes these abnormalities or whether these abnormalities cause anxiety is like trying to discover the proverbial, “Which came first, the chicken or the egg”?
- To date, the exact cause of panic disorder remains unknown.
Many experts believe that panic disorder develops from a combination of genetic, biological and environmental sources. Hopefully, future research will delineate and tie together these, and, perhaps, other unknown, causes of panic disorder.
Sources:
American Psychiatric Association. "Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision" 2000 Washington, DC: Author.
Carbonell, D. "Panic Attacks Workbook" 2004 Berkley, CA: Ulysses Press.
Kaplan MD, Harold I. and Sadock MD, Benjamin J. "Synopsis of Psychiatry, Eighth Edition" 1998 Baltimore: Williams & Wilkins.
