Arousal and stress reactions are essential for human survival. They enable people to pursue important goals and to respond appropriately to danger. In a healthy individual, the stress response (fight, fright, or flight) is provoked by a genuine threat or challenge and is used as a spur for appropriate action.
An anxiety disorder, however, is an excessive or inappropriate arousal characterized by feelings of apprehension, uncertainty, or fear. The word is derived from the Latin, angere, which means to choke or strangle. The anxiety response is often not attributable to a real or appropriate threat; nevertheless it can still paralyze the individual into inaction or withdrawal. An anxiety disorder also persists, while a healthy response to a threat resolves once the threat is removed.

Physically, anxiety is usually expressed through a group of responses that include the following:


rise in blood pressure.
A rapid heart rate.
Rapid breathing.
An increase in muscle tension.
Nausea or diarrhea (from reduced blood flow in the intestine).
Anxiety disorders have been classified according to the severity and duration of their symptoms and specific behavioral characteristics; categories include:
 

Generalized anxiety disorder (GAD), which is long-lasting and low-grade.
Panic disorder, which has more dramatic symptoms.
Phobias.
Performance anxiety.
Obsessive-compulsive disorder (OCD).
Post-traumatic stress disorder (PTSD).
GAD and panic disorder are the most common. Anxiety disorders are usually caused by a combination of psychological, physical, and genetic conditions, and treatment is, in general, very effective.


Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is the most common anxiety disorder and affects about 5% of Americans over the course of their lifetimes. It is characterized by the following:
 

A more-or-less constant state of tension and anxiety over various situations.
This state lasts more than six months despite the lack of an obvious or specific stressor.
It is very difficult for a person with GAD to control worry. For a clear diagnosis of GAD, the specific worries should be differentiated from those that would define other anxiety disorders, such as fear of panic attacks or appearing in public, nor are they obsessive as in obsessive-compulsive disorder. (It should be noted, however, that over half of those with GAD also have another anxiety disorder or depression.)
Patients may experience anxiety physically (such as with gastrointestinal complaints) in addition to, or even in place of, mental worries. (This latter case may be a particularly problem in people from non-Western cultures, such as those with Asian backgrounds.)
Given these conditions, a diagnosis of GAD is then confirmed if three or more of the following symptoms are present (only one for children) on most days for six months:
 

Being on edge or very restless.
Feeling tired.
Having difficulty with concentration.
Being irritable.
Having muscle tension.
Experiencing sleep disturbances.
Symptoms should cause significant distress and impair normal functioning and not be due to a medical condition or to another mood disorder or psychosis.
 

Panic Disorder

Panic disorder is characterized by periodic attacks of anxiety or terror (panic attacks), they usually last 15 to 30 minutes, although residual effects can persist much longer. The frequency and severity of acute states of anxiety determine the diagnosis. (It should be noted that panic attacks can occur in nearly every anxiety disorder, not just panic disorder. In other anxiety disorders, however, there is always a cue or specific trigger for the attack. A diagnosis of panic disorder is made under the following conditions:
 

When a person experiences at least two recurrent, unexpected panic attacks.
These are followed by at least one month of fear that another will occur.


Symptoms of a Panic Attack. During a panic attack a person feels intense fear or discomfort with at least four or more of the following symptoms:
Rapid heart beat.
Sweating.
Shakiness.
Shortness of breath.
A choking feeling.
Dizziness.
Nausea.
Feelings of unreality.
Numbness.
Either hot flashes or chills.
Chest pain.
A fear of dying.
A fear of going insane.
Panic attacks that include only one or two symptoms, such as dizziness and heart pounding, are known as limited-symptom attacks. These may be either residual symptoms after a major panic attack or precursors to full-blown attacks.

Frequency of Panic Attacks. Frequency of attacks can vary widely. Some people have frequent attacks (for example, every week) that occur for months; others may have clusters of daily attacks followed by weeks or months of remission.

Triggers of Panic Attacks. Panic attacks may occur spontaneously or in response to a particular situation. Recalling or reexperiencing even harmless circumstances surrounding an original attack may trigger subsequent panic attacks. (It should be noted that panic attacks can also accompany other anxiety disorders, such as phobias and posttraumatic stress disorder. In such cases, however, additional characteristics differentiate these disorders from panic disorder.)


Phobic Disorders

Phobias, manifested by overwhelming and irrational fears, are common. In most cases, people can avoid or at least endure phobic situations, but in some cases, as with agoraphobia, the anxiety associated with the feared object or situation can be incapacitating.

Agoraphobia. Although up to one-half of people with panic disorders who participate in studies have agoraphobia, some experts observe that the majority of panic disorder patients who come to them for treatment also have agoraphobia. Agoraphobia has been somewhat misleadingly described as fear of open spaces, the term having been derived from the Greek word agora meaning marketplace. In its severest form, agoraphobia is characterized by a paralyzing terror of being in places or situations from which the patient feels there is no escape or accessible help in case of an attack. (One patient described the terror of going outside as opening a door onto a landscape filled with snakes.) Consequently, agoraphobes confine themselves to places in which they feel safe, usually at home. The patient with agoraphobia often makes complicated plans in order to avoid confronting feared situations and places.

Social Phobia. Social phobia is the fear of being publicly scrutinized and humiliated and is manifested by extreme shyness and discomfort in social settings. The associated symptoms vary in intensity, ranging from mild and tolerable anxiety to a full-blown panic attack; symptoms include sweating, shortness of breath, pounding heart, dry mouth, and tremor. The disorder is defined as generalized or specific social phobia:

Generalized social phobia includes fear of being humiliated in front of other people while doing various activities, such as writing in the presence of others or urinating in a public bathroom.


Specific social phobia usually involves a phobic response to a specific event. Performance anxiety, or stage fright, is the most common specific social phobia. It occurs when a person must perform in public. The incidence of social phobia is approximately 13% and has been termed "the neglected anxiety disorder" because it is often missed as a diagnosis.


Simple, or Specific, Phobias. A simple, or specific, phobia is an irrational fear of specific objects or situations. Simple phobias are among the most common medical disorders. Most cases are mild, however, and not significant enough to require treatment.
The most common phobias are fear of animals (usually spiders, snakes, or mice), flying (pterygophobia), heights (acrophobia), water, public transportation, confined spaces (claustrophobia), dentists (odontiatophobia), storms, tunnels, and bridges.

When confronting the object or situation, the phobic person experiences panicky feelings, sweating, avoidance behavior, difficulty breathing, and a rapid heartbeat; the only exception is fear of a blood-producing injury, in which the heart rate slows down. Most phobic individuals are aware of the irrationality of their fear, and many endure intense anxiety rather than disclose their disorder.

 

Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) has been described as hiccups of the mind. OCD is time-consuming, distressing, and can disrupt normal functioning. Much research suggests that a critical feature in this disorder is an overinflated sense of responsibility, in which the patient's thoughts center around possible dangers and an urgent need to do something about it

Obsessions are recurrent or persistent mental images, thoughts, or ideas. The obsessive thoughts or images can range from mundane worries about whether one has locked a door to bizarre and frightening fantasies of behaving violently toward a loved one.

Compulsive behaviors are repetitive, rigid, and self-prescribed routines that are intended to prevent the manifestation of an associated obsession. Such compulsive acts might include repetitive checking for locked doors or unlit stove burners or calls to loved ones at frequent intervals to be sure they are safe. Some people are compelled to wash their hands every few minutes or spend inordinate amounts of time cleaning their surroundings in order to subdue the fear of contagion.
Over half of OCD sufferers have obsessive thoughts without the ritualistic compulsive behavior. Although individuals recognize that the obsessive thoughts and ritualized behavior patterns are senseless and excessive, they cannot stop them in spite of strenuous efforts to ignore or suppress the thoughts or actions. OCD often accompanies depression or other anxiety disorders. There is some evidence that the symptoms improve over time and that nearly half will eventually recover completely or have only minor symptoms.

Associated Obsessive Disorders. Certain other obsessive disorders that may be part of the OCD spectrum include the following:


Body dysmorphic disorder (BDD). In BDD, people are obsessed with the belief that they are ugly.
Trichotillomania. People with trichotillomania continually pull their hair, leaving bald patches.
Tourette's syndrome. Symptoms of Tourette's syndrome include jerky movements, tics, and uncontrollably uttering obscene words.


Obsessive-Compulsive Personality. OCD should not be confused with obsessive-compulsive personality, which defines certain character traits (eg, being a perfectionist, excessively consciousness, morally rigid, or preoccupied with rules and order). These traits do not necessarily occur in people with obsessive-compulsive disorder, which is a psychiatric condition.

Post-Traumatic Stress Disorder Post-traumatic stress disorder (PTSD) is an extreme and usually chronic emotional reaction to a traumatic event that severely impairs ones life; it is classified as an anxiety disorder because of the similarity of symptoms.

Triggering Events. PTSD is triggered by violent or traumatic events that are usually outside the norm of human experience. The symptoms are the same whether the triggering event is a violent action or natural disaster. Such events include, but are not limited to, experiencing or even witnessing sexual assaults, accidents, combat, natural disasters (such as earthquakes), or unexpected deaths of loved ones. PTSD may also occur in people who have serious illness and receive aggressive treatments or who have close family members or friends with such conditions.

Warning Symptoms: Acute Stress Disorder. Experts have identified a syndrome called acute stress disorder, which occurs within two days to four weeks after the traumatic event, and can help predict who is at highest risk for PTSD. To be diagnosed with acute stress disorder, victims should meet these criteria:

 

They are exposed to traumatic events in which they witness or have been confronted by an actual or potential threat of death, serious injury, or physical harm (such as rape) to themselves or others.
Their response is one of fear, helplessness, or horror. In addition, during or after these experiences, they must have three or more of the following: an emotional numbness, being in a daze, a sense of losing contact with external reality, a feeling of loss of self or identity, or inability to remember important aspects of the event. (Such symptoms indicate a psychological state known as dissociation.)
They persistently re-experience the trauma in at least one of the following ways: in recurrent images, thoughts, flashbacks, dreams, or feelings of distress at situations that remind them of the traumatic event.
They avoid reminders of the event, such as thoughts, people, or any other factors that trigger recollection.
They have symptoms of anxiety or heightened awareness of danger (sleeplessness, irritability, being easily startled, or becoming overly vigilant to unknown dangers).
The emotional state significantly impairs normal function and relationships, and they fail to seek necessary help.
The condition occurs within four weeks of the event and lasts for at least two days and up to four weeks.
The condition is not due to alcohol, medications, or drugs and is not an intensification of a pre-existing psychological disorder.
The criteria for acute stress disorder are accurate at identifying up to 94% of victims at risk for PTSD, and between 50% and 80% actually develop the more chronic and serious disorder. In other words, it is very sensitive for identification of those at highest danger for PTSD but less successful in determining specifically who will or will not recover emotionally.

Symptoms of PTSD. They are usually similar to those of acute stress syndrome with certain differences:

 

Symptoms of PTSD can occur months or even years after the traumatic event.
They last beyond a month and are much more severe.
They are chronic (three months or more).
Other symptoms of PTSD may include:
 

Emotional withdrawal.
Phobic avoidance of reminders of the trauma that become severe enough to impair personal and work relationships.
Hopelessness.
Self-destructive behavior.
Personality changes.
Mood swings.
Difficulty with sleep.
Other anxiety disorder.
Guilt over surviving the event.
Children may engage in play or actions in which the events are repetitively enacted.


Long-Term Outlook. The long-term impact of a traumatic event is uncertain. In one study of people who survived a mass killing spree in Texas, less than half of those who suffered PTSD (28% of all survivors) had recovered after a year. In another study, PTSD became chronic in 46% of the subjects. In fact, PTSD may cause actual physical changes in the brain and can last a lifetime in some cases.



What Causes Anxiety Disorders?

A person's genetics, biochemistry, environment, history, and psychological profile all seem to contribute to the development of anxiety disorders. Most people with these disorders seem to have a biological vulnerability to stress, making them more susceptible to environmental stimuli than the normal population.

Biochemical Factors

Abnormalities in the Brain. Scientists are now beginning to identify different areas of the brain associated with anxiety responses using advanced imaging techniques, particularly magnetic resonance imaging (MRI):
Some MRI scans have revealed over-activity in the locus coeruleus (a part of the brain important in triggering a response to danger) in people experiencing anxiety.

Some scans have detected abnormalities in the amygdala, a part of the brain that regulates fear, memory, and emotion and coordinates them with heart rate, blood pressure, and other physical responses to stressful events.

Abnormalities in a pathway of nerves, referred to as the basal-ganglia thalamocortical pathway, have been linked to OCD, attention deficit disorder, and Tourette's syndrome. The symptoms of the three disorders are similar and they often coexist.

One study using MRI imaging suggested that some children who develop OCD have a larger than average thalamus, which is a major messages center in the brain.

Neurotransmitters. Studies suggest that an imbalance of certain substances called neurotransmitters (chemical messengers in the brain) may contribute to anxiety disorders. They include norepinephrine, dopamine, serotonin, and gamma-aminobutyric acid (GABA). For instance, abnormalities in GABA and serotonin may have a particular role in susceptibility to generalized anxiety disorder. Serotonin is also a major player in OCD.

Dysfunctional Respiratory System. Some interesting research suggests that rather than fear triggering a physical response, the opposite may occur. Experts theorize that some people with anxiety disorders have an abnormality in their breathing that causes them to be very sensitive to carbon dioxide (CO2), resulting in hyperventilation (in which the breathing is rapid and the heart rate is fast). The condition may be aggravated in situations with high levels of CO2, which can occur in crowded spaces, such as airplanes or elevators. In such circumstances, the patient hyperventilates. Because such a response also occurs during danger, the individual becomes frightened. Over time a series of such responses creates a pattern of impaired breathing and panic that involves into a full-fledged anxiety disorder.



Genetic Factors
Up to half of people with panic disorder have close relatives with the disorder, and about 20% of people with generalized anxiety have relatives with the same disorder. (About half of GAD patients also have family members with panic disorder, and about 30% have relatives with simple phobias.) OCD is also strongly related to a family history of the disorder. Researchers are looking for specific genetic factors that might contribute to an inherited risk.
 

A 1999 study identified a possible genetic defect in OCD patients that affects serotonin, a neurotransmitter important in anxiety disorders. Earlier, researchers identified a gene that produces lower amounts of serotonin in people who have personality traits that include anxiety, anger, hostility, impulsiveness, pessimism, and depression. (Such a gene, however, would account for only a very small fraction of people with anxiety disorders.)
Genetic mutations that affect other neurotransmitters have also been identified that contribute to obsessive-compulsive disorder.
Some experts have identified a genetic defect that affects dopamine, another important neurotransmitter, which appears to cause a syndrome that includes migraine headaches, anxiety, and depression.
Family Dynamics
The influence of the family on anxiety is complicated by both genetic and psychological factors. Many patients with anxiety disorders appear to report parents who were at once overprotective and unaffectionate. One study suggested that stressful events, such as disagreements with parents, act upon internalized emotions in young adolescents. Eventually these feelings build up and produce full-blown anxiety or depressive disorders in young adulthood.
Panic Disorder and Family Influence. Certain psychodynamic theories suggest and some studies support the idea that panic disorder may be caused by the inability to solve the early childhood conflict of dependence vs. independence. (In one study, young adults who had experienced childhood anxiety were more likely to live with their parents until their early to mid-twenties.) Many people with panic disorder perceive their parents as being extremely controlling and overly protective while showing little actual affection.

Phobias and Family Influence. Several studies show a strong correlation between a parent's fears and those of the offspring. Although an inherited trait may be present, some researchers believe that many children can even "learn" fears and phobias just by observing a parent or loved one's phobic or fearful reaction to an event. People who have severe agoraphobia with or without panic disorder generally report less parental affection and more strictness, overprotection, and encouragement of dependence than those without these disorders. One 2000 study found similar traits in parents of children with social phobias. Such parents were also likely to have social phobias and depression.

Obsessive Compulsive Disorder and Family Influence. One study found that parental influence played no part in obsessive-compulsive disorder if the patient was also not suffering from depression. (Patients who had both OCD and depression reported lower levels of parental care and overprotectiveness.) It should be noted, however, that depression coexists in two-thirds of OCD patients.

 

Traumatic Events
Traumatic events can trigger anxiety disorders, the most obvious being post-traumatic stress disorder, although there usually need to be other psychological, genetic, or biochemical factors that make one susceptible to anxiety afterwards. Specific traumatic events in childhood, particularly those that threaten family integrity, such as spousal or child abuse, can lead to post-traumatic stress and other anxiety and emotional disorders. Some individuals may even have a biological propensity for specific fears, for instance of spiders or snakes, that can be triggered and perpetuated after a single first exposure.
 

Other Factors
Anxiety can be a chronic symptom of other psychologic or medical problems, such as depression, substance abuse, or thyroid disease. A number of studies have reported a strong link between childhood rheumatic fever, which is caused by a streptococcal infection, and the development of tic-related disorders, including OCD and Tourette's syndrome. The effects of alcohol on the developing fetus now appear to increase the risk for mental disorders as well as birth defects.



Who Gets Anxiety Disorders?


Risk Factors for Anxiety in General
Age. Anxiety disorders are the most common psychiatric condition in the United States. Anxiety disorders affect more than 23 million Americans, and as many as 25% of all American adults experience intense anxiety at sometime in their lives. The prevalence of severe anxiety disorders is much lower, however. Although worry is very common among children and is often intense, only about 5% have anxiety that can be classified as a disorder. Depression is a common companion in such children.
Gender. With the exception of OCD and possibly social anxiety, women have twice the risk for most anxiety disorders than men do. A number of factors may increase the risk in women, including hormonal factors, cultural pressures to meet everyone else's needs except their own, and less self-restrictions on reporting anxiety to physicians.

Family History. Anxiety disorders run in families. Although family dynamics and psychologic influences are often at work, genetic factors may also play a role in many cases.

Personality. Studies have suggested that extremely shy children and those likely to be the target of bullies are at higher risk for developing anxiety disorders later in life. One study suggests that such children could be identified as early as two years of age and possibly treated to avoid later anxiety disorders.

Socioeconomic Factors. A study of Mexican adults living in California reported that native-born Mexican-Americans were three times more likely to have anxiety disorders (and even more likely to be depressed) as those who had recently immigrated to the US. And the longer the immigrants lived in the US the greater was their risk for psychiatric problems. Traditional Mexican cultural effects and social ties, then, appear to protect newly arrived immigrants from mental illness, even when they are poor. Eventually, however, the consequences of Americanization lead to depression and anxiety, probably resulting from feelings of alienation and inferiority, not only in many Mexican Americans, but in other impoverished minority groups.

 

Risk Factors for Generalize Anxiety (GAD)
Age and GAD. GAD affects about 5% of Americans for the course of their lives. The risk for generalized anxiety disorder spans a lifetime although it appears to be the most common form of anxiety at older ages. One study reported that depression in adolescence was a strong predictor of generalized anxiety disorder (GAD) in adulthood.
 

Risk Factors for Panic Disorder
Age and Panic Disorder. Studies indicate that the prevalence of panic disorder among adults is between 1.6% and 2%. Studies report a prevalence of 3.5% to 9% of panic disorders in adolescents, which is much higher than in adults. Panic disorders tend to begin in late adolescence and peak at around 25 years of age. In one study, 18% of adult patients with panic disorder reported the onset of the disorder before 10 years of age.
Gender and Panic Disorder. Women have about twice the risk for panic disorder than men do. The effects of pregnancy on panic disorder appear to be mixed; it seems to improve the condition in some women and worsen it in others.

Medical Conditions that Accompany Panic Disorder. People with certain medical conditions are also at risk for panic disorder, although no causal relationships have been established. Such conditions include migraines, mitral valve prolapse, irritable bowel syndrome, chronic fatigue syndrome, hyperventilation syndrome, and premenstrual syndrome.

 

Risk Factors for Obsessive-Compulsive Disorder (OCD)
Age and OCD. OCD affects about 2% to 3% of people over a lifespan. About 80% of cases, show signs in childhood, although the disorder usually develops fully in adulthood.
Gender and OCD. Obsessive-compulsive disorder occurs equally in both genders.

Risk Factors for Social Phobias
Age and Phobias. The onset of social anxiety disorder usually occurs in adolescence, although most people with this disorder are not diagnosed and do not receive treatment until or unless they develop an accompanying anxiety disorder.
Gender and Phobias. Like other anxiety disorders, the rates of social phobia are higher in women. Unlike their response to other emotional disorders, however, men are more likely than women to seek treatment for this disorder, probably because social phobias can interfere strongly with many jobs in white-collar professions.

 

Risk Factors for Post-Traumatic Stress Disorder
Studies estimated a lifetime risk for PTSD of about 0.8% in men and 1.2% in women. Specific groups, such as combat troops, have a much higher incidence. Among adolescents, studies have found the prevalence of PTSD to be as high as 8.1%.
Simply experiencing a traumatic event, however, does not predict post-traumatic stress disorder. Studies estimated that between 6% to 30% or more of trauma survivors develop PTSD, with children being among those at the high end of the range. In one study, for example, 60% of children injured in accidents suffered from PTSD, with 40% experiencing it for six months. Researchers are trying to determine factors that might increase vulnerability to catastrophic events and put people at risk for develop PTSD:

A psychiatric illness. One study reported that having a pre-existing emotional disorder, particularly depression, before the traumatic event most often predicted PTSD in women.
Drug or alcohol abuse.
A family history of anxiety.
A history of abuse, particularly that which threatens family integrity, such as spousal or child abuse. Studies of individuals who had suffered physical or sexual abuse or neglect as children suggest that up to a third develop PTSD.
An early separation from parents.
 
How Serious are Anxiety Disorders?

Studies consistently report that all anxiety disorders can be very debilitating and impinge seriously upon a person’s quality of life.

 

Association with Depression
In one report, over half of patients with depression met the criteria for anxiety disorders. The combination of depression and anxiety is a major risk factor for both substance abuse and suicide.
Depression and nearly every anxiety disorder often go hand in hand, in both the young and old, The following are examples:

Between 20% and 75% of people with panic attacks also have major depression.
More than two-thirds of OCD patients also suffer from depression.
Generalized anxiety disorder and social phobia are more likely to precede depression while panic disorder and agoraphobia are more likely to follow depression.
People with PTSD are four to seven times as likely to be depressed as are people without PTSD.
According to one interesting 2000 study of teen-agers, anxiety disorders were associated with later bipolar disorders (manic-depression) in adulthood, while, conversely, manic behavior in adolescence appeared to increase the risk for adult anxiety disorders.
Increased Risk for Suicide
Studies suggest that 18% of people with panic disorder attempt suicide and up to 30% harbor suicidal thoughts. One study reported suicide attempts in about 12% of people with social phobias or OCD.
Whether anxiety disorder intensifies the risk in people who are depressed is uncertain. One 2000 study suggested an association between generalized anxiety and suicidal thoughts or attempts in older adults with depression. Interestingly, in another 2000 study, patients with panic disorder and major depression were no more likely to attempt suicide than depressed patients without the anxiety disorder. In fact, agitation and anxiety were associated with a lower risk for suicide attempts in depressed people.

 

Alcoholism and Substance Abuse
Severely depressed or anxious people are at high risk for alcoholism, smoking, and other forms of addiction. Anxiety disorders are highly prevalent among people with alcoholism.
Risk for Specific Anxiety Disorders. While some people with GAD and panic disorders may use alcohol or drugs to self-medicate, social phobia appears to pose a particular risk for alcohol abuse. People with this disorder are likely to drink in order to boost confidence. (Specific phobias, interestingly, do not pose such a risk.) Alcohol itself has no direct beneficial effect on anxiety, but studies suggest that the belief in its effect appears to reduce anxiety. It should be noted, moreover, that long-term alcohol use can itself cause biologic changes that may actually produce anxiety and depression.

Post-Traumatic Stress Disorder and Substance Abuse. According to two studies, there is growing evidence that heavy smoking and substance abuse are prevalent in people with PTSD. Certainly PTSD in adolescence increases the risk for drugs, alcohol, and eating disorders.

 

Effects on Work, School, and Relationships
Studies consistently report negative effects of anxiety disorders on work and relationships. In one survey of OCD sufferers, for example, 40% reported that they had to stop working because of the disorder; only 40% worked full-time, and only half were married. In another study, people with social phobia were more likely than others to drop out of school or to report lower functioning. (The absence of depression did not improve their experience.)
Effects on Physical Health
People with panic disorder perceive their own physical and emotional well being as poor and seek medical help more often than do those in the general population. Any causal connection between anxiety and medical disorders is unclear.
Effects on the Heart. Studies have reported that between 25% and 60% of patients with chest pain who see a physician for possible heart problems suffer instead from panic disorder. Although a 1998 study found reason to fear that anxiety caused heart disease in either men or women, some researchers speculate that intense anxiety might trigger abnormal and dangerous heart rhythms in people with existing heart problems. In fact, panic disorders and phobias have been associated with a higher rate of sudden death from cardiac events. In another study of Vietnam veterans, PTSD sufferers had double the risk for abnormal heart rhythms and four times the risk of a heart attack compared to men without PTSD. Another study indicated that people who experience anxiety are more likely to develop high blood pressure than are those who are not anxious. Both anxiety and depression have been associated with a poor response to treatment in heart patients.

Effects on the Gastrointestinal Tract. Anxiety frequently accompanies medical conditions; for example, half the cases of irritable bowel syndrome are related to anxiety.

Effects on Headache. One study reported that 32% of people with chronic tension headaches met criteria for anxiety. It isn't clear whether the psychologic disorder preceded or followed the onset of headaches. Similarly, another study reported that young girls with anxiety disorder were three times more likely to have chronic headaches than those without the disorder. (Headaches in both these studies were also strongly associated with depression.)

Effects on Sleep Disorders in Children. One study of children linked anxiety with a higher risk for sleep disorders, such as frequent nightmares, restless legs, and bruxism-- grinding and gnashing of the teeth during sleep.

Physical Effects of Post-Traumatic Stress Disorder. Some studies on people, including military veterans, who have endured major traumatic events, have found a higher risk for health problems. One study of Vietnam veterans reported that PTSD was associated with greater physical limitations, poorer physical health, and a lower quality of life than in those in the normal population, regardless of other accompanying emotional or medical disorders. (Studies suggest that combat stress itself does not have a major impact on health.)

Other Disorders. People with obsessive-compulsive disorders can experience skin problems from excessive washing, injuries from repetitive physical acts, and hair loss from repeated hair pulling, a specific OCD known as trichotillomania.

 

Effect of PTSD on the Brain
Studies are reporting that PTSD is associated with shrinkage in the hippocampus, the part of the brain important for memory and learning. Studies of animals indicate that such damage may result from long term exposure to cortisol, the major stress hormone. Groups who had suffered severe trauma also scored 40% lower in tests of verbal memory than the general population. There was no difference in IQ or in scores of other types of memory. One study suggests that exposure to chronic stress, common in PTSD patients, may compromise the function of the brain’s receptors for benzodiazepinea (a class of medications used to treat anxiety).