Anxiety is often a healthy response to uncertainty and danger, but constant worry and nervousness can be a sign of another kind of trouble, internal rather than external. Severe anxiety is a common symptom of many psychiatric disorders, from hypochondriasis and anorexia to major depression and schizophrenia --in some ways, a lowest common denominator of mental illness. It's also the dominant symptom in a group of disorders that includes social phobia, panic disorder, specific phobias, and post-traumatic stress disorder.
But generalized anxiety disorder (GAD) is the only condition characterized chiefly by debilitating worry and agitation about nothing in particular or anything at all. Although it may be the most common anxiety disorder, we know less about GAD than we do about most of the others. Still, it can often be effectively treated with several kinds of medication and psychotherapy.
The constant and continually changing worries of people with GAD are mostly about everyday matters. They can't shake the feeling that something bad will happen and they will not be prepared. They may worry to excess about missing an appointment, losing a job, having an accident, or possible illness in the family. Worries may also extend to the improbable or irrelevant --one of the characters in a Woody Allen film was troubled by the thought that the universe is expanding. Some people even worry about worrying too much, just as others are kept awake by anxiety about not getting enough sleep. Physical symptoms are also an integral part of the disorder -racing heart, dry mouth, upset stomach, muscle tension, sweating, trembling, and agitation.
About 5% of people have GAD at some time in their lives, and two-thirds of them are women. More than half of adults who seek treatment for GAD say the symptoms first appeared in childhood or adolescence (in children, similar symptoms are called overanxious disorder). Generalized anxiety disorder tends to be chronic. One study found that nine years after the diagnosis, 25% of patients were significantly impaired, nearly half had moderate to severe symptoms, and only a little over 10% of patients had recovered fully. Another study found that on average GAD lasted five years and recurrence was common.
Many people with GAD have other anxiety disorders, and a third suffer from major depression at some time in their lives. In fact, GAD is sometimes difficult to distinguish from chronic moderate depression (dysthymia). The two disorders have many symptoms in common and similar treatments, and they apparently run in the same families. (The American Psychiatric Association has listed "mixed anxiety-depression disorder" in its manual as a diagnosis for further study.) GAD is also associated with the personality disorders described as the anxious cluster -avoidant personality, dependent personality, and obsessive-compulsive personality.
The biology of anxiety
Like all animals, human beings are equipped by evolution to anticipate and avoid danger. Fear is our emergency reaction to an immediate threat, and anxiety is the form of fear that persists when the threat is more remote. It concentrates the mind, helping us to anticipate danger and make plans. Lying just beneath the cerebral cortex, the amygdala serves as the brain's headquarters for responses to danger. It sends messages to the hypothalamus, at the base of the brain, provoking the release of hormones that raise heart rate and blood pressure, tense the muscles, and generally ready the body for action. Meanwhile, the nearby hippocampus is directed to form explicit memories of the circumstances for future reference, and alarms set the cerebral cortex to thinking.
Through these processes we form mental associations that teach us what to fear. If a tone is sounded repeatedly when a laboratory rat receives a shock, the rat eventually shows fear when it hears the tone even if no shock follows. Because it's vital, this mechanism has to be sensitive, but that means it can easily become hypersensitive. We may begin to anticipate danger everywhere. Anxiety becomes attached to situations, thoughts, and memories unrelated to genuine sources of fear. Eventually, conscious thoughts themselves can activate the amygdala, causing us to create our own fears. Experiments show that objects of fear existing only in imagination stimulate some of the brain systems associated with fears acquired through experience.
Scientists are beginning to learn why some people are easily agitated or worry too much. They may be congenitally susceptible to learned anxiety, possibly because of an overactive amygdala. Severe or constant stress can also produce a hyperactive anxiety reaction; the most striking example is post-traumatic stress disorder. Other experiences, especially early in life, may also heighten vulnerability to anxiety. Some believe that's what happens when parents are overprotective, suggesting that danger is everywhere, or so inconsistent in their behavior that everything seems unpredictable and uncontrollable.
At the biochemical level, neurotransmitters and hormones regulate fear and anxiety. The response to these chemical messengers can be abnormal for various reasons. Receptors may be too sensitive or insensitive, and the supply of a neurotransmitter may be insufficient or excessive because too much or too little is released or absorbed.
The stress hormones that play a role in anxiety reactions are produced by glands and travel in the bloodstream. On a signal from the amygdala, the hypothalamus and pituitary gland cause the adrenal glands to secrete the hormones cortisol and adrenaline. This circuit, the hypothalamic-pituitary-adrenal (HPA) axis, is stabilized by feedback from high levels of cortisol in the blood. Some people who are chronically anxious or depressed may have a hyperactive HPA axis, with poor regulation of stress hormones.
The neurotransmitters associated with anxiety and its relief are gamma-aminobutyric acid (GABA), norepinephrine, and serotonin. GABA signals nerve cells to stop firing immediately and await further instructions. Serotonin and norepinephrine, acting more slowly, regulate the responsiveness of circuits governing mood, stress responses, and conditioned fears. All prescription anti-anxiety drugs alter the action of one or more of these neurotransmitters. Benzodiazepines act at receptors for GABA; antidepressants act at receptors for norepinephrine, serotonin, or both.
According to family and twin studies, the heritability of GAD (the proportion of individual differences associated with a genetic difference) is about 30%. Brain scans indicate that the amygdala's response to pictures of frightening faces depends partly on variants of a serotonin transporter gene --one that carries serotonin back into the neuron that released it. Laboratory rats show high anxiety as adults when their early brain development has been distorted by the removal of a gene needed to construct one of the serotonin receptors. Mice bred for reduced numbers of GABA receptors show greater and more indiscriminate anxiety in many situations. Still, there are no genetic tests for susceptibility to anxiety disorders, and the results of research on neurotransmitters are inconclusive. No theory fully explains the neurochemistry of anxiety.
Talk (and action) therapy
People with GAD can use many other kinds of help apart from medications. Supportive psychotherapy provides reassurance, suggestions, advice, sympathy, and a better understanding of the disorder. A few studies have found that breathing exercises, progressive muscle relaxation, and biofeedback are more effective than supportive therapy alone. Hypnosis may help patients to focus and relax. Some may benefit from the discussion of experiences that have made them susceptible to anxiety.
The most carefully studied psychotherapeutic treatment for anxiety symptoms is cognitive-behavioral therapy. Its purpose is to expose and correct bias, misinterpretation, and unjustified generalization in people's everyday thoughts and perceptions. Errors in thinking are traced to "automatic thoughts" -- unquestioned notions that are difficult to challenge because they rarely become explicit. They are regarded as the effect of underlying "schemas" -- unconscious ways of organizing experience and assigning meaning. An example of an anxiety-provoking schema: "It's always best to anticipate the worst."
As cognitive-behavioral therapists see it, people with GAD misperceive events, magnify difficulties, and make pessimistic assumptions on little evidence. They perceive more threats than others, pay more attention to anything that seems threatening, and incorporate a vague sense of danger into all their thinking. They worry constantly in an attempt to define and describe their problems, reducing anxiety temporarily but in the end maintaining the feeling that they lack control. Anticipation of disaster and the physical symptoms of anxiety are mutually reinforcing.
The treatment usually requires 6-12 weekly therapy sessions, along with homework. Patients are asked to keep a diary for recording and examining their thoughts and feelings, with special attention to those that cause or relieve anxiety. The therapist helps them to become aware of automatic thoughts and underlying schemas so that they can make vague worries more specific, evaluate them, and expose them as unrealistic.
It's usually not enough to correct errors in thinking. The behavioral side of cognitive-behavioral therapy involves learning new ways to solve problems and respond to anxiety-provoking situations. Patients may receive problem-solving skills training and learn how to set goals and establish priorities. The methods include role-playing, rehearsal, and modeling (learning by imitation).
A 1999 review of five controlled studies found that six months after completing cognitive-behavioral therapy, about 60% of patients with GAD were somewhat improved, although fewer than 40% fully recovered. Individual cognitive-behavioral therapy was more effective than group therapy, behavior therapy alone, or supportive therapy alone. There's little research comparing talk therapy with drugs in the treatment of GAD. Three studies have found cognitive-behavioral therapy equal or superior to benzodiazepines, although the drugs work faster. There are no direct comparisons of cognitive-behavioral therapy with antidepressants in GAD, although one study found that an antidepressant was superior for anxiety in depressed patients. A combination of cognitive-behavioral therapy and medication may be more effective than either alone, especially for long-term results.
Too often, the treatments known to be effective aren't being used. A 1999 survey indicated that although most patients with generalized anxiety and other anxiety disorders were given some medication, only 40% received a high enough dose for a long enough time. Cognitive-behavioral therapy was even more neglected. Fewer than a third of patients had any behavioral or cognitive treatment, and the numbers receiving any kind of talk therapy had been declining during the 1990s. Everyday practice needs to change to keep pace with growing knowledge about the causes and treatment of anxiety.
Generalized anxiety disorder defined
Generalized anxiety disorder is excessive anxiety and worry that is difficult to control and causes serious distress or interferes with daily activities. These symptoms occur more days than not for at least six months, along with at least three of the following:
• restlessness or feeling on edge
• tiring easily
• difficulty concentrating
• muscle tension
• sleep problems
The symptoms are not the result of a medical condition, a medication, or a nonmedical drug, and they don't occur only during a mood disorder, a psychotic disorder, or post-traumatic stress disorder. The symptoms do not necessarily include fear of specific objects (simple phobias), fear of having a panic attack (panic disorder), fear of being embarrassed in public (social phobia or performance anxiety), fear of being contaminated (obsessive-compulsive disorder), fear of gaining weight (anorexia), or fear of having a serious illness (hypochondriasis).
The article above contains foundational information. Articles below contain optional updates.
- Harvard Mental Health Letter, Jan2003
Reflection Exercise #7
The preceding section contained information
about generalized anxiety disorder. Write
three case study examples regarding how you might use the content of this section
in your practice.
Online Continuing Education QUESTION 21
What is the purpose of cognitive-behavioral therapy in treating anxiety? Record the letter of the correct answer