[Editor's note: This article is from 2007. Some newer treatments and current statistics are not included here. See further information on BrainWeb]
sections include: generalized anxiety disorder, panic disorder, understanding anxiety disorders, diagnosis and treatment
Anxiety is a normal human emotion. We all feel anxious sometimes. The emotion is helpful when it motivates a person to avoid danger or to work hard at difficult or unpleasant tasks that will ultimately bring rewards. At other times, however, anxiety becomes abnormal and harmful, especially in the conditions known as generalized anxiety disorder (GAD) and panic disorder (PD).
Generalized Anxiety Disorder
People with GAD generally experience excessive worry and tension for most of their lives. They may not realize that anything is wrong or unusual with this state because chronic anxiety has become their way of life. But their worry is out of proportion to any real threat. Often people with GAD search their lives for reasons to be so worried, hoping to find an explanation for their feelings. These rationales can be quite convincing. They help explain the usual accompanying symptoms: insomnia, muscle tension, and a variety of aches and pains, including headache and gastrointestinal problems. Those physical problems are products of the tension, but they are also real. They are generally the reason people with GAD first seek medical care. Chronically anxious people rarely seek help for an emotional problem because they do not recognize they may have one.
Left untreated, GAD can cause major, ongoing difficulties. People with this condition are generally unable to remember a moment in their lives when they were calm or relaxed. Their excessive worry makes it difficult for them to complete important tasks. They can transmit high levels of anxiety to their loved ones, often burdening children with excessive fears. The disorder’s most dire complication is the onset of major depression, which most people with GAD will suffer unless their problem is recognized and treated. Evidence suggests that people with GAD also suffer from higher rates of some medical problems—for example, hypertension and irritable bowel syndrome—but cause-and effect relationships between these problems have never been established.
In contrast to people with GAD, those with panic disorder generally feel well until they experience the first in a series of panic attacks. These are short-lived events (lasting between 10 and 20 minutes), characterized by a crescendo of fear and physical symptoms cued by the autonomic nervous system. Typically, a panic attack includes a suddenly accelerating heart rate, difficulty breathing, shaking, light-headedness, and sweating. People suffering one feel a sense of impending catastrophe. Usually they assume they are in the midst of a grave medical event, like a heart attack, and seek emergency medical attention for that.
If an individual’s PD is not identified after the first attack, the condition can become extremely debilitating. Repeated unexplained panic attacks often lead people to become anxious, worrying that another attack will occur, and to develop phobias. The sufferers avoid situations in which they have had attacks in the past, or places where they might have a hard time finding help if one begins. For example, people with PD typically try not to drive in rush hour, travel on subways or planes, sit in crowded theaters, or go to shopping malls. In the worst case, they develop agoraphobia, not leaving the house unless accompanied by a companion they trust to obtain help immediately if an attack occurs. Clearly, the disorder can interfere with an individual’s normal social functioning.
People suffering from PD are also at high risk of developing depression; when they do, they face an increased risk of suicide attempts. PD is also associated with migraine headaches, irritable bowel syndrome, asthma and other chronic respiratory diseases, problems with the heart’s mitral valve, and increased risk of cardiovascular disease.
Understanding Anxiety Disorders
Because there is no visible, rational cause for the anxiety that people with GAD and PD feel, it is tempting to believe that they can get over their symptoms if they just try hard enough. Sometimes these people are even accused of fabricating their symptoms to get attention. Those notions are clearly false. Though GAD and PD can both be mild, they usually impair a person’s life severely. Because of their incessant worry, people suffering from GAD tend to become ineffective and paralyzed when trying to complete important tasks. Those with PD may be unable to do most tasks outside their homes. Both groups frequently resort to alcohol or other abusable substances, and their rates of depression are very high.
Over our lifetimes, about 5 percent of people will suffer from GAD, and 3.5 percent from PD. PD is about twice as common in women as in men. A person is several times more likely to develop PD if a close genetic relative has the disorder. Studies of fraternal and identical twins suggest that inheritance determines about 40 percent of the risk for panic attacks. Data also suggests that a person’s risk for PD increases if he or she has suffered significant emotionally traumatic events during childhood, such as the death of a parent, the divorce of parents, or sexual or physical abuse. Both conditions can wax and wane but rarely vanish spontaneously without returning.
A great deal of research in recent years has indicated that both GAD and PD may involve abnormalities in the activity of specific brain circuits, and that these conditions involve both genetic predisposition and exposure to adverse life events. Most scientists now believe that anxiety disorders involve hyperactivity in a channel of the central nervous system called the fear network. This involves the central nucleus of the amygdala, its projections to parts of the brain stem involved in autonomic nervous system responses and freezing behavior (that is, sudden immobility due to fear), and its connections to the hippocampus and to the medial prefrontal cortex. Studies have implicated a number of neurotransmitters in the disorders, including excessive activity of noradrenaline in particular areas of the brain and deficient activity of serotonin. We also believe that these anxiety disorders may involve excessive activity of corticotrophin-releasing factor and glutamate, the amino acid most important in exciting the brain.
Another view of anxiety disorders is that the brain has become unable to calm down, to stop being excited. Drugs known as benzodiazepines are effective against anxiety because they bind to a specific receptor in the brain and thereby improve the effects of the brain’s major inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). This may indicate that anxiety disorders involve abnormalities in this system as well.
Diagnosis and Treatment
As pointed out above, people with GAD and PD often suspect they are suffering from other problems and can exhibit many physical symptoms. A physician must consider and rule out a wide range of conditions before diagnosing an anxiety disorder. On the other hand, people with anxiety disorders should not be subjected to endless medical evaluations. There is evidence that early treatment of anxiety disorders can prevent many of their complications, such as depression and severe phobic avoidance; delay in treatment worsens a person’s prognosis.
In general, a person suspected of having GAD or PD should undergo medical evaluation based on the immediate complaints, his or her medical history, and routine medical recommendations. Doctors must rule out other psychiatric diagnoses as well, and this can also be challenging. People with anxiety disorders have elevated rates of alcohol and other substance abuse, and acute drug or alcohol withdrawal can mimic panic attacks. Other conditions to exclude are somatization disorder, bipolar disorder, and anxiety associated with psychotic illnesses.
As described above, anxiety disorders and depression often appear together. Many people with PD and GAD also suffer from specific fears, social phobia, obsessive-compulsive disorder, and post-traumatic stress disorder.
Psychiatrists and some family physicians specialize in treating GAD and PD. There are two forms of treatment that have proven effective for most anxiety disorders: cognitive behavioral therapy (CBT) and medications. CBT generally involves weekly or biweekly sessions with a doctor for about three to four months. These sessions focus on education about one’s disorder, training in healthy breathing to stop hyperventilation, learning to think in new ways about one’s condition, and gradual exposure to the situations that one associates with the anxiety. It is important that the clinician administering this therapy be specifically trained to provide CBT for anxiety disorders.
Medications for GAD include benzodiazepines, buspirone (BuSpar), and antidepressants. Two antidepressants, venlafaxine XR (Effexor) and paroxetine (Paxil), have been approved by the Food and Drug Administration (FDA) for this purpose.
For PD, the medications include antidepressants and benzodiazepines. Most physicians agree that the first drugs to try are antidepressants of the selective serotonin reuptake inhibitor (SSRI) class: paroxetine (Paxil) and sertraline (Zoloft). The FDA has also approved two benzodiazepines—alprazolam (Xanax) and clonazepam (Klonopin)—for treating panic disorder.
Treatment for anxiety disorders is highly successful at helping a person over immediate problems. Most patients respond well to CBT or medication, and combining the two treatments may be more effective than either alone. Approximately 80 percent of people with GAD and PD respond to a short, intense course of treatment over about 12 weeks. Studies now suggest that remission of symptoms can be long-lasting following a successful course of CBT; improvement often continues for more than a year. This may be due in part to normalization of some aspects of brain function that continue even after the treatment has been completed. Some research is now being conducted to see if “booster sessions” at approximately monthly intervals improve long-term remission rates.
For people who do not respond to CBT, some studies suggest that adding medication may then be helpful. It is not yet known whether repeated courses of CBT are helpful for people who initially respond but then later relapse. Relapse rates after a person with an anxiety disorder stops taking medication are generally high, between 30 and 40 percent, although some data suggest that using effective medication for a year or more may reduce this risk, at least for PD patients. As long as patients remain on medication, relapse is uncommon. Some patients therefore choose to stay on their prescribed drugs for prolonged periods. Long-term use of antidepressants is generally safe and well-tolerated, although some patients experience weight gain, sleep disturbance, and sexual problems. Venlafaxine is also associated with increased blood pressure in some people.
A great deal of research is now going on to identify further risk factors for anxiety disorders in our genes and our early experiences. Ultimately we may be able to prevent the conditions from arising. The concerted effort to study the brain networks and physiology involved in these disorders may result in better treatments. And psychiatrists are doing research to maximize the benefits people can receive from standard courses of cognitive behavioral therapy and medication.
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