Anxiety was first recognized as a medical diagnostic entity in the late 1800s. Before this time, anxiety was considered a feature of many medical conditions. In 1871, Jacob DaCosta described a chronic cardiac syndrome that included many psychological and somatic symptoms exhibited by soldiers. This “irritable heart syndrome” due to autonomic cardiac symptoms was later referred to as the DaCosta syndrome. World War II veterans and other survivors of combat exhibited a similar cluster of symptoms due to severe stresses that was eventually identified as post-traumatic stress disorder (PTSD; Sadock & Sadock, 2003).

Sigmund Freud first introduced the concept of anxiety in the early 1900s. He referred to it as a danger signal that a person exhibits in response to the perception of physical pain or danger. He recognized anxiety as a central component of mental diseases.

The term anxiety is used to describe feelings of uncertainty, uneasiness, apprehension, or tension that a person experiences in response to an unknown object or situation. A “fight-or-flight” decision is made by the person in an attempt to overcome conflict, stress, trauma, or frustration.

Fear is different from anxiety. It is the body’s physiologic and emotional response to a known or recognized danger. A person whose car stalls on a railroad crossing experiences fear of injury or death as the train approaches the crossing. The client who undergoes emergency exploratory surgery may be afraid of the surgery and develop symptoms of anxiety because the client is uncertain what the outcome will be.

Several terms have been used to describe different types of anxiety. They include signal anxiety, anxiety trait, anxiety state, and free-floating anxiety. Signal anxiety is a response to an anticipated event. For
example, a father who normally is relaxed exhibits tachycardia, dizziness, and insomnia when his child attends school for the first time. He is experiencing signal anxiety.

An anxiety trait is a component of personality that has been present over a long period and is measurable by observing the person’s physiologic, emotional, and cognitive behavior. The person who responds to various nonstressful situations with anxiety is said to have an anxiety trait. For example, a 25-year-old secretary frequently complains of blurred vision, dizziness, headaches, and insomnia in a relatively stress-free job.

An anxiety state occurs as the result of a stressful situation in which the person loses control of her or his emotions. A mother who is told that her son has been injured in a football game and has been taken to the emergency room may exhibit an anxiety state by becoming hysterical, complaining of tightness in the chest, and insisting on seeing her injured son.

Free-floating anxiety is anxiety that is always present and is accompanied by a feeling of dread. The person may exhibit ritualistic and avoidance behavior (phobic behavior). A woman who is unable to sleep at night because she is certain someone will break into her home goes through a complicated ritual of checking all the windows and doors several times. She also avoids going out after dark because she fears coming back to a dark, empty home.

Genetic studies have produced solid evidence that at least some genetic component contributes to the development of anxiety disorders (Sadock & Sadock, 2003). In 1996, researchers at the National Institute of Mental Health determined that the gene 5-HTTP influences how the brain makes use of serotonin. Statistics indicated that the gene caused a 3% to 4% difference in the degree of anxiety or tension the subjects experienced. Findings from this same study were also used to explore the origins of normal and pathological personality patterns.

Family studies have been conducted to determine the prevalence of anxiety in relatives. Two methods are generally used: the family history, which relies on indirect interviews with an informant, and the family study, which is based on direct interviews of family members. These methods have been used to explore theories regarding various classifications of anxiety (Nicolini, Cruz, Camarena, Paez, & De La Fuente, 1999). For example, almost half of all clients with panic disorder have at least one affected relative; about 15% to 20% of individuals with obsessive–compulsive disorder (OCD) come from families in which another immediate family member has the same problem; and about 40% of people with agoraphobia have a relative with agoraphobia (Sadock & Sadock, 2003).

Some studies have suggested that a relatively simple genetic model may explain the genetic or inheritance pattern of anxiety. The hypothesis states that there are some genes that play a major role, contributing to the manifestation of clinical symptoms of anxiety. For example, recent data provide strong evidence that chromosome 9 may be linked to the development of panic disorder; chromosome 13q may be linked to a potential subtype of panic disorder called “panic syndrome”; and significant linkage was found at chromosome 14 for simple phobia, and possible linkages for social phobias, panic disorder, and agoraphobia. Data regarding potential linkages at chromosome 1 for panic disorder, chromosome 3 for agoraphobia, chromosome 11 for panic disorder, and chromosome 16 for social and simple phobia have also been reported (Norton, 2004).

In general, studies have evaluated the links between anxiety and the following: catecholamines; neuro-endocrine measures; neurotransmitters such as serotonin, γ-aminobutyric acid (GABA), and cholecystokinin; and autonomic reactivity. Neuroimaging studies have also been performed (Sadock & Sadock, 2003).

Studies evaluating catecholamine levels (eg, epinephrine and norepinephrine) have shown that these levels in clients with anxiety appear to be similar to those of normal control clients. Neuroendocrine studies have been inconclusive.

Neurotransmitter studies have revealed that serotonin plays a role in causing anxiety. Specifically, excessive serotonin activity in critical brain areas such as the raphe nucleus, hypothalamus, thalamus, basal ganglia,
and limbic system may relate to anxiety. Agents such as buspirone and benzodiazepines inhibit serotonin transmission, which leads to the relief of anxiety symptoms (Roerig, 1999).

Neuroimaging research focuses on normal anatomy and neurochemistry, and behavioral, pharmacologic, and cognitive challenge theories to understand the biologic basis of anxiety. Research focuses on identifying potential predictors of treatment response. For example, positron emission tomography (PET) studies have shown increased metabolic activity and blood flow in the frontal lobes, basal ganglia, and the cingulum of clients with the diagnosis of OCD (Holman & Devous, 1992; Sadock & Sadock, 2003).

Laboratory studies have shown that a panic attack is characterized by a sudden increment in tidal volume rather than in respiratory frequency. In these studies, a computerized, calibrated body suit (Respitrace) was used to allow 24-hour recordings. Results have shown that clients who have spontaneous panic attacks experience a tripling of respiratory tidal volume.

Studies also have attempted to study the correlation between anxiety and heart disease. Kawachi, Sparrow, Vokonas, and Weiss (1994) examined the relationship between anxiety symptoms and the risk of coronary heart disease. This study concluded that there is a strong association between symptoms of anxiety and the presence of coronary artery disease.

Psychoanalytic theory originates in the work of Sigmund Freud, who suggested that anxiety is the result of unresolved, unconscious conflicts between impulses for aggressive or libidinal gratification and the ego’s recognition of the external damage that could result from gratification. For example, unconscious conflicts of childhood, such as fear of losing a parent’s love or attention, may emerge and result in feelings of discomfort or anxiety in childhood, adolescence, or early adulthood (Roerig, 1999).

A newer psychodynamic theory proposes that anxiety is an interaction between temperament and environment. Clients enter the world with an inborn physiologic reactivity that predisposes them toward early fearfulness. As they struggle with dependency conflicts, they develop weak representations of themselves and use poor strategies, such as avoidance, to cope with life stresses. Their feelings of safety decrease, and they develop a loss of control along with an increase of negative emotions, culminating in anxiety and an initial panic attack (Medscape, 2000).

The cognitive behavior theory, developed by Aaron Beck, suggests that anxiety is a learned or conditioned response to a stressful event or perceived danger. According to this theory, conceptualization or faulty, distorted, or counter-productive thinking patterns accompany or precede the development of anxiety. For example, individuals may perceive certain somatic sensations, such as heart palpitations or jittery feelings, as considerably more dangerous than they truly are. The individuals then interpret these sensations as indicating that they are about to experience sudden, imminent danger. Further, these misinterpretations may arise from fear and other emotions or from stimuli such as caffeine or exercise (Roerig, 1999). Clinical Example 19-1 illustrates two different cognitive reactions to the same stressful event.

Social–cultural theorists believe integrated social or cultural factors cause anxiety. As a person’s personality develops, his or her impression of self may be negative
(low self-concept). The person experiences difficulty adapting to everyday social or cultural demands because of this low self-concept and inadequate coping mechanisms. The stressful stimuli of society and one’s culture pose a psychological threat for such a person, possibly resulting in the development of maladaptive behavior and the onset of an anxiety disorder. For example, a 19-year-old man has difficulty maintaining a C average in high school and does not fit in with his peers. He works as a delivery person for a pizza company. As he makes a delivery, he receives a traffic ticket for driving with a faulty muffler. The police officer informs him that he will not be fined if he replaces the defective muffler within 24 hours. The young man makes an appointment to have his car fixed. However, his employer says he cannot allow him to take the time off. The young man becomes tense and experiences feelings of dizziness, tachycardia, and shortness of breath as he responds to his employer’s comment. Because of inadequate coping mechanisms, he is unable to consider alternate options, such as asking the employer to use the company car for a day or suggesting that he change work schedules with another employee. His low self-concept prevents him from pointing out to his employer that he has been a faithful employee with a good work record, and therefore his request should receive special consideration due to the nature of the problem. Unless this young man develops a positive self-concept and adequate coping mechanisms, he will continue to experience difficulty dealing with the stress of daily social or cultural problems.

Panic disorder is a real illness with both a physical and a psychological component. This debilitating condition affects approximately 1.7% (2.4 million) of the adult U.S. population and has a very high comorbidity rate with major depression. The onset usually begins during the late teens or early twenties. Although it can occur in both men and women, women are twice as likely to be afflicted as are men (ADAA, 2003).

Three types of panic attacks have been identified. Typically, an individual’s first panic attack seems to occur “out of the blue” while the person is engaged in some ordinary activity such as grocery shopping, driving a car, or doing housework. The individual suddenly experiences frightening and uncomfortable symptoms that may include terror, a sense of unreality, or a fear of losing control. Such unexpected panic attacks occur without warning and for no discernable reason, as noted above.

Situational panic attacks occur in response to specific environmental stimuli or events that are anxiety producing (eg, riding in an elevator or flying on an airplane). Situationally predisposing panic attacks refer to an attack with the likelihood or potential to reoccur when an individual’s anxiety level increases. If the client is able to utilize anxiety-reducing coping skills, the likelihood of a panic attack’s reoccurring decreases (Richards, 2003).

The differential diagnosis for a client with panic disorder includes a large number of medical disorders (eg, cardiovascular, pulmonary, endocrine, or neurologic diseases, or electrolyte imbalances) and many psychiatric–mental health disorders (eg, drug intoxications, drug withdrawal, eating disorders, or cognitive disorders). After the presence of an immediately life-threatening condition is ruled out, the clinical suspicion is panic disorder (Sadock & Sadock, 2003).

According to DSM-IV-TR diagnostic criteria, panic attacks are not caused by the direct physiologic effects of a substance or a general medical condition, and they are not better accounted for by another mental disorder.
Panic attacks usually last between 1 minute and 1 hour. The intensity of the attacks may fluctuate considerably in the same person (NIMH, 2000). See the accompanying Clinical Symptoms and Diagnostic Characteristics box.

The client develops these symptoms suddenly, with the symptoms increasing in intensity within minutes of awareness of the first sign. For example, chest pain occurs, followed by three other symptoms that increase in intensity within 10 minutes of the onset of chest pain. (The diagnosis here would be Panic Disorder Without Agoraphobia.) See Clinical Example 19-2.

During the panic attack, the individual may experience a fear of being alone in a public place (agoraphobia). Most researchers believe agoraphobia develops as a complication in clients with panic disorder; that is, clients have a fear of having a panic attack in a public place from which escape would be difficult (Sadock & Sadock, 2003). (See discussion of phobias in the next section.) The diagnosis then would be Panic Disorder With Agoraphobia. After a panic attack, the individual exhibits concern about having additional panic attacks, worries about implications of the attack or its consequences, or displays a significant change in behavior (APA, 2000). About one in three people with panic disorder develop agoraphobia (NIMH, 2005).

Phobias are the most common form of mental disorders among women and second among men, affecting 8% (11.5 million) of adult Americans (ADAA, 2003; Sadock & Sadock, 2003). A phobia is described as an irrational fear of an object, activity, or situation that is out of proportion to the stimulus and results in avoidance of the identified object, activity, or situation. The person unconsciously displaces the original internal source of fear or anxiety, such as an unpleasant childhood experience, to an external source. Avoidance of
the object or situation allows the person to remain free of anxiety.

A phobic reaction can be so mild that it hardly affects a person’s life. The feared object or situation may enter the person’s life so rarely that the phobia does not interfere with daily functioning. Other phobias, such as fear of water, may prohibit common activities such as taking a shower or brushing one’s teeth. Three major types of phobias are described here.