Panic Attacks and Panic Disorder

	Topic Overview
	Health Tools
	Cause
	Symptoms
	What Happens
	What Increases Your Risk
	When To Call a Doctor
	Exams and Tests
	Treatment Overview
	Prevention
	Home Treatment
	Medications
	Surgery
	Other Treatment
	Other Places To Get Help
	Related Information
	References
	Credits

What are panic attacks and panic disorder?

A panic attack is a sudden, intense fear or anxiety that may make you short of breath or dizzy or make your heart pound. You may feel out of control. Some people believe they are having a heart attack or are about to die. An attack may last from 5 to 20 minutes. You have the most anxiety about 10 minutes after the attack starts. If these attacks happen often, they are called a panic disorder.

Panic attacks can be scary and so bad that they get in the way of your daily activities. Treatment can help most people have fewer symptoms or even stop the attacks.

More women than men get panic attacks.

What causes panic attacks and panic disorder?

Experts aren't sure what causes panic attacks and panic disorder. But the body has a natural response when you are stressed or in danger. It speeds up your heart, makes you breathe faster, and gives you a burst of energy. This is called the fight-or-flight response. It gets you ready to either cope with or run away from danger. A panic attack occurs when this response happens when there is no danger.

Panic attacks and panic disorder may be caused by an imbalance of brain chemicals or a family history of panic disorder. They sometimes happen with no clear cause.

Panic attacks may also be brought on by:

• A health problem such as an overactive thyroid (hyperthyroidism), or heart or breathing problems.
• Depression or another mood disorder.
• Alcohol abuse.
• Using too much nicotine or too much caffeine.
• Taking certain medicines, such as those used to treat asthma and heart problems.
• Using illegal drugs such as marijuana or cocaine.
• Living with high levels of stress for a long time.

You have a higher chance of getting panic disorder if you have a parent with depression or bipolar disorder.

What are the symptoms?

Symptoms of a panic attack may include:

• A feeling of intense fear, terror, or anxiety.
• Trouble breathing or very fast breathing.
• Chest pain or tightness.
• A heartbeat that races or is not regular.
• Sweating.
• Nausea or an upset stomach.
• Dizziness and shaking.
• Numbness or tingling.

Symptoms of panic disorder may include:

• Repeated panic attacks when there is no reason for the fight-or-flight response.
• Changing your daily activities because you worry that you will have another attack.

Some people have a fear of being in crowds, standing in line, or going into shopping malls. They are afraid of having another panic attack or of not being able to escape. This problem is called agoraphobia and can be so bad for some people that they never leave their homes.

About half of people who have panic disorder also have agoraphobia.¹ People with panic disorder often have depression at the same time.

How are panic attacks and panic disorder diagnosed?

Your doctor will ask about your past health and do a physical exam. The exam may include listening to your heart, checking your blood pressure, and ordering blood tests to look for other causes of your problem. Your doctor may ask you to do some simple things that test your memory and other mental skills.

How are they treated?

Treatments for panic attacks and panic disorder include counseling and medicine. Using both will often work best. Treatment can help most people control or even stop attacks. But symptoms can come back, especially if you stop treatment too soon.^{2, 1}

Early treatment of panic attacks is very important. It can prevent other problems related to panic disorder. These problems include depression, anxiety disorders, and substance abuse.

Frequently Asked Questions

Health tools help you make wise health decisions or take action to improve your health.

	Decision Points focus on key medical care decisions that are important to many health problems.
	Should I take medications to treat panic disorder?

The exact cause of panic disorder is not clear. It is thought that panic disorder may result from an imbalance of chemicals in the brain (neurotransmitters).

Panic disorder also may be passed down through families (genetic). Children of parents who have panic disorder are up to 8 times more likely to develop panic disorder.³ You are also at a higher risk of developing panic disorder if you have a parent with either depression or bipolar disorder.^{4, 5} Stressors (such as the sudden loss of a relationship) may trigger symptoms of panic disorder as well.

You may experience a panic attack without having panic disorder. Panic attacks may be triggered by:

• Drinking large amounts of alcohol or abruptly stopping the use of alcohol.
• Drinking large amounts caffeinated beverages.
• Chain-smoking, which causes the amount of nicotine in the blood to be very high.
• Taking certain medications (such as those used to treat asthma and heart conditions) or abruptly stopping certain medications (such as those used to treat anxiety or sleep problems).
• Using illegal drugs, such as cocaine or marijuana.
• Having high levels of stress for a long time (chronic stress).
• Having recently had a baby.
• Having recently had surgery or been under general anesthesia.

Panic attacks also can be caused by or associated with other medical conditions, including:⁶

• Thyroid problems, such as an overactive thyroid (hyperthyroidism).
• Heart problems, such as mitral valve prolapse.
• Seizure disorders, such as epilepsy.
• Asthma.
• Respiratory problems, such as chronic obstructive pulmonary disease (COPD).
• Stopping the use of a prescription medication, such as a heart medication.
• Depression.
• Anxiety disorders such as post-traumatic stress disorder or obsessive-compulsive disorder.

The main symptom of a panic attack is an overwhelming feeling of fear or anxiety, along with physical reactions. The symptoms come on suddenly, often unexpectedly, and the intensity usually peaks within 10 minutes. Although most symptoms fade within 30 minutes, it may take up to an hour for all the symptoms to go away completely. It is possible to have one panic attack after another in waves for an extended period of time, and it can seem like one continuous attack. However, if you have continuous symptoms that do not go away within an hour, you probably are not having a panic attack and you should seek immediate medical care.

Symptoms of a panic attack may include:³

• Rapid breathing (hyperventilation), shortness of breath, or feeling "smothered."
• A pounding or racing heart or an irregular heartbeat.
• Chest pain.
• Lightheadedness.
• Sweating.
• A choking feeling.
• Nausea or an upset stomach.
• Dizziness, shaking, or trembling.
• Numbness or tingling.
• Chills or hot flashes.
• Fear that you are going to die, lose control, or "go crazy."
• Feelings of being detached from yourself or from reality.

Panic attacks can begin with a stressful event or appear without cause. They also can be associated with medications, such as heart medications, and medical conditions, such as an overactive thyroid (hyperthyroidism).

Panic attacks may begin without a trigger or can be linked to certain situations, such as being in large crowds of people in restaurants or stadiums. Sometimes just the anticipation of being in a certain situation can cause severe anxiety. People who experience panic attacks often learn to avoid situations that they fear will trigger a panic attack or situations where they will not be able to escape easily if an attack occurs. If this pattern of avoidance and anxiety is severe, it can become agoraphobia.

The symptoms of a panic attack can be similar to those of a heart attack. Many people seek emergency medical treatment for a panic attack for this reason. If you have chest pain and other symptoms of a heart attack, seek immediate medical treatment. For more information, see the topic Chest Pain.

Panic attacks are not common in children or younger teens. But children who have panic disorder or panic attacks often have other symptoms in addition to those listed above. They may be overly afraid of common objects such as bugs, or worry excessively about monsters or about going to bed alone. They also may refuse to go to school or become unusually upset when they are separated from a parent.

Not everyone who experiences panic attacks develops panic disorder. A person is diagnosed with panic disorder if he or she has at least two unexpected panic attacks along with fear or worry about having another panic attack and avoiding situations that may trigger it.³

You may be diagnosed with panic disorder after several unexpected panic attacks and if you continue to fear having another attack. These panic attacks can have mild to severe symptoms and usually last less than 30 minutes.

A first panic attack often starts without warning during an ordinary activity such as shopping or walking down the street. You may become confused and think you are "going crazy" or that something terrible is going to happen. You may feel a strong need to leave the area and go to a place that feels safe, such as your car or home. You may also experience physical symptoms such as shortness of breath, a pounding heart, or chest pain. The intensity of these symptoms usually peaks within 10 minutes. It is common to think you are experiencing a heart attack and to seek treatment in a hospital emergency room.

Panic attacks may be triggered by a specific action, such as drinking too much caffeine, or by a situation, such as being in a large crowd. Panic attacks may also start suddenly without a known trigger. You may greatly fear having another panic attack (anticipatory anxiety) and avoid all social situations (agoraphobia). As many as half of people who have panic disorder also have agoraphobia.¹ Isolating yourself and avoiding social situations can interfere with your ability to work and your relationships, especially with your family members and close friends.

Other characteristics that are common in panic disorder include:

• Fearing sleep and feeling exhausted from lack of sleep.
• Using drugs or alcohol (to numb your fears or give you a false sense of courage to face feared situations).
• Having depression.
• Having irrational fears (phobias).
• Experiencing other anxiety disorders, such as post-traumatic stress disorder.
• Having difficulty relating to other people in social settings due to intense feelings of anxiety.

Although the first panic attack may occur during a routine activity, for many people it happens at the same time during their life when there is a lot of stress, such as a life-threatening illness or accident, the loss of a relationship, or separation from family. Sometimes an initial panic attack may occur after giving birth.

It is also possible for a first panic attack to occur as the result of a drug reaction or a reaction to nicotine or caffeine. However, after the situation that caused the first panic attack is resolved, attacks may continue. Experts believe these stressful circumstances may start the cycle of panic attacks in people who are already prone to panic disorder.⁷

Recurrent panic attacks can be mild to severe and continue for years, especially if you also have agoraphobia (avoiding places where you fear another attack will occur).⁸ You may have long periods of time without panic attacks and other periods of time when attacks occur frequently.

You may need longer or different treatment if you have both panic disorder and agoraphobia. You may also experience other conditions associated with panic disorder and panic attacks such as drug or alcohol problems, depression, or other mental health disorders. You will need treatment for all these conditions.

Panic disorder may last a lifetime, but its symptoms can be controlled with treatment. Most people with panic disorder get better with treatment. They are able to get back to a normal lifestyle, although relapse can occur, especially if treatment is discontinued too soon.^{2, 1}

The risk of having panic attacks and developing panic disorder may be higher if you:

• Have a family history of panic disorder. You are 8 times more likely to develop panic disorder if a family member has been diagnosed with it.¹ You are also at increased risk if you have a parent with either depression or bipolar disorder.^{4, 5}
• Have other conditions associated with panic disorder or panic attacks, such as depression.
• Drink alcohol, use illegal drugs, chain-smoke cigarettes, or drink large amounts of coffee or other caffeinated beverages.
• Take medications known to trigger panic attacks, such as those used to treat asthma or heart problems.
• Have mitral valve prolapse, a heart condition in which one of the valves in the heart does not close as it should.
• Have had previous, unexpected panic attacks.
• Have experienced an episode of major depression.
• Are a woman who has recently gone through menopause.⁹

Call your health professional if you experience:

• Attacks of intense fear or anxiety that seem to come on without a reason.
• A panic attack or worry that you will have another one and your worrying interferes with your ability to do your daily activities.
• Occasional physical symptoms (such as shortness of breath and chest pain) and you are not sure what is causing them.

Watchful Waiting

It can be difficult to tell the difference between the symptoms of a panic attack (such as shortness of breath and chest pain) and the symptoms of a heart attack or another serious medical problem. If you have symptoms of a panic attack, you should seek immediate medical care so that other medical conditions can be ruled out.

Who To See

The following health professionals can diagnose panic attacks and may work together with other health professionals to treat panic attacks and panic disorder:

• Emergency medicine specialist
• Family medicine physician
• General practitioner
• Physician assistant
• Nurse practitioner

Treatment for panic attacks and panic disorder may also be provided by a:

• Psychiatrist.
• Psychologist.
• Licensed professional counselor.

Many community mental health centers, hospital outpatient clinics, and family service agencies have treatment programs for people with panic disorder.

To prepare for your appointment, see the topic Making the Most of Your Appointment

Panic disorder usually is diagnosed through a medical history and a physical exam. The health professional will ask you questions about your symptoms and will listen to your heart, check your blood pressure, and may order blood tests. The health professional may need to rule out other physical conditions that have symptoms similar to panic disorder, such as a heart attack, mitral valve prolapse, or hyperthyroidism.

Panic disorder can be controlled with medications (such as antidepressants) and professional counseling (such as cognitive-behavioral therapy). Successful treatment reduces the number and frequency of panic attacks, lowers the anxiety you feel because of the fear of future attacks, and improves the quality of your life.

If your panic attacks were caused by a specific trigger, such as a medication reaction, you may not need treatment after the trigger has been removed, which in this case would mean stopping the medication with the help of your health professional. However, sometimes panic attacks caused by outside factors can continue after the trigger has been removed and may develop into panic disorder.

Initial treatment

Initial treatment for panic disorder depends upon how bad your panic attacks are, how much fear or anxiety you feel about having another attack, and whether you have agoraphobia (avoiding situations or places that might trigger an attack) along with panic disorder.

Generally, initial treatment includes:

• Professional counseling.
  • Cognitive-behavioral therapy, which focuses on modifying certain thinking and behavior patterns, is the most effective type of therapy for panic disorder.
  • Exposure therapy is a type of cognitive-behavioral therapy that focuses on confronting a feared object or situation. It can be especially helpful in treating agoraphobia or anxiety linked to a particular place or situation.
• Medications.
  • The most common medications used to treat panic disorder are selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), sertraline (Zoloft), or paroxetine (Paxil). If these medications are not effective or do not work because of their side effects, other antidepressants may be tried.
  • Antidepressants with mixed neurotransmitter effects, such as venlafaxine (Effexor) are sometimes used.⁷
  • Benzodiazepines such as alprazolam (Xanax), diazepam (for example, Valium), lorazepam (Ativan), or clonazepam (Klonopin) sometimes are prescribed either alone or combined with an antidepressant. Benzodiazepines are most commonly used for rapid, short-term relief of symptoms and may also be used as a part of ongoing treatment either alone or combined with an antidepressant.
  • Other antidepressants used to treat panic disorder include tricyclic antidepressants (TCAs) such as imipramine (Tofranil), desipramine (Norpramin), or clomipramine (Anafranil) and monoamine oxidase inhibitors (MAOIs) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate).

Your symptoms of panic disorder may start to improve within a few weeks after beginning medications. If improvement is not seen within 6 to 8 weeks, a higher dose or another medication may be needed.¹⁰

Should I take medication to treat panic disorder?

Ongoing treatment

Treatment for recurring or ongoing panic disorder usually consists of continuing or changing initial measures, which include professional counseling and medications.

During initial treatment, a short-term medication such as a benzodiazepine may be prescribed to help you deal with immediate symptoms. The short-term medication will likely need to be tapered off and stopped after long-term medications begin working and your symptoms improve.

You will be continually assessed to determine whether you have developed any other conditions associated with panic disorder, such as depression or problems with drugs or alcohol. These additional conditions will also need treatment.

An important part of ongoing treatment is making sure you are taking your medication as prescribed. Often people who feel better after using medication for a period of time may believe they are "cured" and no longer need treatment. But when medication is stopped, symptoms usually return, so it is important that you continue the treatment plan.

Recurrent panic attacks can be mild to severe and continue for years, especially if you also have agoraphobia (avoiding places where you fear another attack will occur).⁸ You may have long periods without panic attacks or times when attacks occur frequently. Even after treatment is stopped because the attacks appear to be under control, attacks can suddenly return. Learn to identify your early warning signs and triggers so you can seek treatment early.

Treatment if the condition gets worse

If your panic attacks become severe or continually recur, you may need to be hospitalized until they are under control. You also may need a brief hospital stay if you have panic attacks along with another health condition, such as agoraphobia or depression, because these conditions combined can be more difficult to treat.

If you are taking medications that do not seem to be helping, your doctor may prescribe a different medication or a combination of medications.

If medication is currently your only treatment, counseling may be added to your treatment. Counseling may include cognitive-behavioral therapy, which focuses on modifying certain thinking and behavior patterns, or exposure therapy, which focuses on confronting a feared object or situation. If you are in counseling, but it does not seem to be working, more intensive, more frequent, or a different type of counseling may be added to your treatment.

If counseling is currently your only treatment, medications may be added.

What To Think About

Although medications to treat panic disorder often may prevent another panic attack, they may not take away the fear of having another attack. Counseling can help you handle this fear. The fear of having an attack may actually bring on another attack.

It can take up to several weeks or longer before a medication becomes fully effective. You may need to try several medications or combinations before you find the one that works best for you.

People who have panic disorder may be at an increased risk for suicide if they also have depression or another mood or personality disorder. These conditions can also have a significant impact on social functioning and quality of life. Diagnosis and treatment of conditions that occur along with panic disorder are essential.

Unfortunately, many people don't seek treatment for anxiety disorders. You may not seek treatment because you think the symptoms are not bad enough or that you can work things out on your own. But getting treatment is important.

If you need help deciding whether to see your doctor, see some reasons why people don't get help and how to overcome them.

Although panic disorder cannot be prevented, you may be able to prevent or reduce the number of additional panic attacks with proper treatment. Simply avoiding certain situations or places does not guarantee that a panic attack will not occur under new circumstances. In fact, avoiding situations and places where panic attacks have occurred often increases your level of anxiety. You may be able to reduce the severity of future attacks by following home treatment practices such as reducing anxiety and limiting triggers like caffeine and alcohol; by continuing medical treatment and counseling, such as exposure therapy; and by calling a health professional if symptoms recur or get worse.

You may be able to decrease the number of panic attacks due to panic disorder and reduce the severity of your symptoms when an attack does occur by:

• Reducing anxiety by doing tension-reducing activities and lowering the amount of stress in your life.
• Doing relaxation exercises which involve 10 to 20 minutes of deep breathing and muscle relaxation daily.
• Getting regular physical exercise that gets your breathing and heart rate up several times per week.
• Restricting alcohol and caffeine (or eliminating these altogether).
• Joining a self-help and support group such as one organized by the Anxiety Disorders Association of America (ADAA).
• Eating a balanced diet, which includes eating fresh, healthy foods and limiting your intake of foods that are high in sugar and fat.

Support for family members

When a person has panic attacks, that person's entire family is affected. If someone in your family has panic attacks, you may feel frustrated, overworked (because you have to take over his or her responsibilities), or socially isolated because the person restricts family activities. These feelings are normal. Family therapy, a type of counseling that involves the entire family, may be helpful for all family members. For more information, see:

How can I help someone who is having a panic attack?

Medications for panic disorder are often used to control the symptoms of panic attacks, reduce their number and severity, and reduce the anxiety and fear associated with having another attack. Medications work best if they are used along with counseling and home treatment, such as relaxation exercises.²

Medication Choices

Medications used most often to treat panic attacks include the following:⁸

• Selective serotonin reuptake inhibitors (SSRIs), such as Prozac, Zoloft, or Paxil
• Benzodiazepines, such as Xanax, Valium, Ativan, or Klonopin

Medications sometimes used to treat panic disorder include the following:

• Antidepressants with mixed neurotransmitter effects, such as venlafaxine (Effexor)⁷
• Tricyclic antidepressants (TCAs), such as Tofranil, Norpramin, or Anafranil
• Monoamine oxidase inhibitors (MAOIs), such as Marplan, Nardil, or Parnate

What To Think About

Panic disorder is best treated with both medications and counseling such as cognitive-behavioral therapy, which focuses on modifying certain thinking and behavior patterns. When these two therapies are combined, relapses of panic attacks occur far less frequently than when only one treatment is used.¹¹

Your symptoms of panic disorder should start to improve within a few weeks after beginning medications. If improvement is not seen within 6 to 8 weeks, a higher dose or another medication may be needed.¹⁰

Most medications used to treat panic attacks need to be continued for a year or longer and then may be decreased gradually over several weeks.¹² If you experience panic attacks again while medications are being stopped, the medications may be continued for at least a few months more. Some people may need to stay on medications for a long time to keep symptoms under control.

You may also need to be reevaluated for other conditions associated with panic disorder, such as depression or substance abuse, because having one of these conditions makes treatment more difficult.^{8, 1}

There is no surgical treatment for panic disorder at this time.

Other treatments for panic disorder include:

• Counseling. Cognitive-behavioral therapy is most effective in treating panic disorder. Other types of counseling you might choose to seek include:²
  • Exposure therapy, a type of cognitive-behavioral counseling.
  • Family therapy, which can help those who care about you learn about panic disorder and help you maintain good relationships.
• Self-help materials, such as instructional videos, books, and audio materials, that can help you learn to cope with panic disorder or anxiety.
• Support groups. Support groups are often good places to share information, problem-solving tips, and emotions related to panic disorder.
• Online discussion forums and Web sites.

Body-centered relaxation exercises can be useful for reducing anxiety and treating symptoms of stress. They include:

• Breathing exercises, such as roll breathing (a type of deep breathing).
• Progressive muscle relaxation, which reduces muscle tension by relaxing individual muscle groups.
• Massage, such as shoulder and neck massage.
• Aromatherapy, which uses the aroma-producing oils (essential oils) from plants to promote relaxation.
• Yoga, tai chi, and qi gong, forms of exercise and meditation. They generally require initial instruction.

Mindfulness activities help relax the mind and are often combined with body-centered relaxation exercises. These include:

• Autogenic training, which is used to return the body to a normal state after a stress response.
• Self-hypnosis, which can open the mind to suggestions that can relieve stress or change the way you respond to stressful situations.
• Meditation, which usually involves slow, regular breathing and sitting quietly for 15 to 20 minutes.
• Guided imagery (visualization), a method of using your imagination to help you relax and release tension caused by stress. Your body responds to the images in your mind. Use these simple imagery exercises for relaxing or renewing your energy when you need to relax.
• Music therapy, which can relax your body, improve your mood, and change the pace of your day.
• Humor therapy, which is becoming widely accepted as a tool for reducing stress and boosting the body's immune system.

Organizations

• Hyperthyroidism
• Mitral Valve Prolapse
• Phobias
• Post-Traumatic Stress Disorder
• Social Anxiety Disorder

Citations

1. American Psychiatric Association (1998). Practice guideline for the treatment of patients with panic disorder. American Journal of Psychiatry, 155(5 Suppl): 1–34.

2. Gorman JM, et al. (2000). Neuroanatomical hypothesis of panic disorder, revised. American Journal of Psychiatry, 157(4): 493–505.

3. American Psychiatric Association (2000). Anxiety disorders. In Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text rev., pp. 429–441. Washington, DC: American Psychiatric Association.

4. MacKinnon DF, et al. (2002). Comorbid bipolar disorder and panic disorder in families with a high prevalence of bipolar disorder. American Journal of Psychiatry, 159(1): 30–35.

5. Biederman J, et al. (2001). Patterns of psychopathology and dysfunction in high-risk children of parents with panic disorder and major depression. American Journal of Psychiatry, 158(1): 49–57.

6. Merritt TC (2000). Recognition and acute management of patients with panic attacks in the emergency department. Emergency Medicine Clinics of North America, 18(2): 289–300.

7. Hollander E, Simeon D (2003). Anxiety disorders. In Textbook of Clinical Psychiatry, 4th ed., pp. 543–565. Washington, DC: American Psychiatric Publishing.

8. Kumar S, Oakley-Browne M (2006). Panic disorder, search date May 2006. Online version of Clinical Evidence (15): 1–15.

9. Smoller JW, et al. (2003). Prevalence and correlates of panic attacks in postmenopausal women: Results from an ancillary study to the Women’s Health Initiative. Archives of Internal Medicine, 163(17): 2041–2050.

10. Nicholas LM, et al. (2004). Panic disorder. In JE Tintinalli et al., eds., Emergency Medicine: A Comprehensive Study Guide, 6th ed., pp. 1826–1830. New York: McGraw-Hill.

11. Greist JH, Jefferson JW (2000). Anxiety disorders. In Review of General Psychiatry, 5th ed., pp. 284–300. New York: Lange Medical Books/McGraw-Hill.

12. Pollack MH, et al. (2003). WCA recommendations for the long-term treatment of panic disorder. CNS Spectrums, 8(Suppl 1): 17–30.

Other Works Consulted

• Barlow DH, et al. (2000). Cognitive-behavioral therapy, imipramine, or their combination for panic disorder. JAMA, 283(19): 2529–2536.

• Cahill SP, Foa EB (2005). Anxiety disorders: Cognitive-behavioral therapy section of Anxiety disorders. In BJ Sadock, VA Sadock, eds., Kaplan and Sadock's Comprehensive Textbook of Psychiatry, 8th ed., vol. 1, pp. 1788–1799. Philadelphia: Lippincott Williams and Wilkins.

• Campbell-Sills L, Stein MB (2006). Guideline Watch: Practice Guideline for the Treatment of Patients With Panic Disorder. Arlington, VA: American Psychological Association. Available online: http://www.psych.org/psych_pract/treatg/pg/Panic.watch.pdf.

• Hayward C, et al. (2000). Predictors of panic attacks in adolescents. Journal of the American Academy of Child and Adolescent Psychiatry, 39(2): 207–214.

• Pace B, Glass RM (2000). Panic disorder. JAMA, 283(19): 2612.

• Pine DS, McClure EB (2005). Panic disorder and agoraphobia section of Anxiety disorders: Clinical features section of Anxiety disorders. In BJ Sadock, VA Sadock, eds., Kaplan and Sadock's Comprehensive Textbook of Psychiatry, 8th ed., vol. 1, pp. 1768–1771. Philadelphia: Lippincott Williams and Wilkins.

• Stein MB (2005). Anxiety disorders: Somatic treatment. In BJ Sadock, VA Sadock, eds., Kaplan and Sadock's Comprehensive Textbook of Psychiatry, 8th ed., vol. 1, pp. 1780–1788. Philadelphia: Lippincott Williams and Wilkins.

• Wulsin L, et al. (2002). A randomized, controlled trial of panic disorder treatment initiation in an emergency department chest pain center. Annals of Emergency Medicine, 39(2): 139–143.