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Anxiety can have a number of different causes. It
is a multidimensional response to stimuli in the person's
environment, or a response to an internal stimulus (for example, a
hypochondriac's reaction to a stomach rumbling) resulting from a
combination of general biological and individual psychological
processes.
Physical
In some cases, anxiety is produced by physical
responses to stress, or by certain disease processes or medications.
THE AUTONOMIC NERVOUS SYSTEM (ANS)
The nervous system of human beings is "hard-wired"
to respond to dangers or threats. These responses are not subject to
conscious control, and are the same in humans as in lower animals.
They represent an evolutionary adaptation to the animal predators
and other dangers with which all animals, including primitive humans,
had to cope. The most familiar reaction of this type is the so-called
"fight-or-flight" reaction. This response is the human organism's
automatic "red alert" in a life-threatening situation. It is a state
of physiological and emotional hyperarousal marked by high muscle
tension and strong feelings of fear or anger. When a person has a
fight-or-flight reaction, the level of stress hormones in their
blood rises. They become more alert and attentive, their eyes
dilate, their heartbeat increases, their breathing rate increases,
and their digestion slows down, allowing more energy to be available
to the muscles.
This emergency reaction is regulated by a part of
the nervous system called the autonomic nervous system, or ANS. The
ANS is controlled by the hypothalamus, a specialized part of the
brainstem that is among a group of structures called the limbic
system. The limbic system controls human emotions through its
connections to glands and muscles; it also connects to the ANS and "higher"
brain centers, such as parts of the cerebral cortex. One problem
with this arrangement is that the limbic system cannot tell the
difference between a realistic physical threat and an anxiety-producing
thought or idea. The hypothalamus may trigger the release of stress
hormones by the pituitary gland, even when there is no external and
objective danger. A second problem is caused by the biochemical side
effects of too many "false alarms" in the ANS. When a person
responds to a real danger, his or her body gets rid of the stress
hormones by running away or by fighting. In modern life, however,
people often have fight-or-flight reactions in situations in which
they can neither run away nor lash out physically. As a result,
their bodies have to absorb all the biochemical changes of
hyperarousal, rather than release them. These biochemical changes
can produce anxious feelings, as well as muscle tension and other
physical symptoms associated with anxiety. They may even produce
permanent changes in the brain, if the process occurs repeatedly.
Moreover, chronic physical disorders, such as coronary artery
disease, may be worsened by anxiety, as chronic hyperarousal puts
undue stress on the heart, stomach, and other organs.
DISEASES AND DISORDERS
Anxiety can be a symptom of certain medical
conditions. Some of these diseases are disorders of the endocrine
system, such as Cushing's syndrome (overproduction of cortisol by
the adrenal cortex), and include over- or underactivity of the
thyroid gland. Other medical conditions that can produce anxiety
include respiratory distress syndrome, mitral valve prolapse,
porphyria, and chest pain caused by inadequate blood supply to the
heart (angina pectoris).
MEDICATIONS AND SUBSTANCE USE
Numerous medications may cause anxiety-like
symptoms as a side effect. They include birth control pills; some
thyroid or asthma drugs; some psychotropic agents; occasionally,
local anesthetics; corticosteroids; antihypertensive drugs; and
nonsteroidal anti-inflammatory drugs (like flurbiprofen and
ibuprofen).
Although people do not usually think of caffeine
as a drug, it can cause anxiety-like symptoms when consumed in
sufficient quantity. Patients who consume caffeine rich foods and
beverages, such as chocolate, cocoa, coffee, tea, or carbonated soft
drinks (especially cola beverages), can sometimes lower their
anxiety symptoms simply by reducing their intake of these substances.
Withdrawal from certain prescription drugs,
primarily beta blockers and corticosteroids, can cause anxiety.
Withdrawal from drugs of abuse, including LSD, cocaine, alcohol, and
opiates, can also cause anxiety.
Learned associations
Some aspects of anxiety appear to be unavoidable
byproducts of the human developmental process. Humans are unique
among animals in that they spend an unusually long period of early
life in a relatively helpless condition, and a sense of helplessness
can lead to anxiety. The extended period of human dependency on
adults means that people may remember, and learn to anticipate,
frightening or upsetting experiences long before they are capable
enough to feel a sense of mastery over their environment. In
addition, the fact that anxiety disorders often run in families
indicates that children can learn unhealthy attitudes and behaviors
from parents, as well as healthy ones. Also, recurrent disorders in
families may indicate that there is a genetic or inherited component
in some anxiety disorders. For example, there has been found to be a
higher rate of anxiety disorders (panic) in identical twins than in
fraternal twins.
CHILDHOOD DEVELOPMENT AND ANXIETY
Researchers in early childhood development regard
anxiety in adult life as a residue of childhood memories of
dependency. Humans learn during the first year of life that they are
not self-sufficient and that their basic survival depends on the
care of others. It is thought that this early experience of
helplessness underlies the most common anxieties of adult life,
including fear of powerlessness and fear of being unloved. Thus,
adults can be made anxious by symbolic threats to their sense of
competence and/or significant relationships, even though they are no
longer helpless children.
SYMBOLIZATION
The psychoanalytic model gives considerable
weight to the symbolic aspect of human anxiety; examples include
phobic disorders, obsessions, compulsions, and other forms of
anxiety that are highly individualized. The length of the human
maturation process allows many opportunities for children and
adolescents to connect their experiences with certain objects or
events that can bring back feelings in later life. For example, a
person who was frightened as a child by a tall man wearing glasses
may feel panicky years later by something that reminds him of that
person or experience without consciously knowing why.
Freud thought that anxiety results from a
person's internal conflicts. According to his theory, people feel
anxious when they feel torn between desires or urges toward certain
actions, on the one hand, and moral restrictions, on the other. In
some cases, the person's anxiety may attach itself to an object that
represents the inner conflict. For example, someone who feels
anxious around money may be pulled between a desire to steal and the
belief that stealing is wrong. Money becomes a symbol for the inner
conflict between doing what is considered right and doing what one
wants.
PHOBIAS Phobias are a special type of
anxiety reaction in which the person's anxiety is concentrated on a
specific object or situation that the person then tries to avoid. In
most cases, the person's fear is out of all proportion to its
"cause." Prior to the Diagnostic and Statistical Manual of Mental
Disorders, 4th edition (DSM-IV), these specific phobias
were called simple phobias. It is estimated that 10-11% of the
population will develop a phobia in the course of their lives. Some
phobias, such as agoraphobia (fear of open spaces), claustrophobia (fear
of small or confined spaces), and social phobia, are shared by large
numbers of people. Others are less common or unique to the patient.
Social and environmental stressors
Anxiety often has a social dimension because
humans are social creatures. People frequently report feelings of
high anxiety when they anticipate and, therefore, fear the loss of
social approval or love. Social phobia is a specific anxiety
disorder that is marked by high levels of anxiety or fear of
embarrassment in social situations.
Another social stressor is prejudice. People who
belong to groups that are targets of bias are at higher risk for
developing anxiety disorders. Some experts think, for example, that
the higher rates of phobias and panic disorder among women reflects
their greater social and economic vulnerability.
Some controversial studies indicate that the
increase in violent or upsetting pictures and stories in news
reports and entertainment may raise the anxiety level of many people.
Stress and anxiety management programs often suggest that patients
cut down their exposure to upsetting stimuli.
Anxiety may also be caused by environmental or
occupational factors. People who must live or work around sudden or
loud noises, bright or flashing lights, chemical vapors, or similar
nuisances, which they cannot avoid or control, may develop
heightened anxiety levels.
Existential anxiety
Another factor that shapes human experiences of
anxiety is knowledge of personal mortality. Humans are the only
animals that appear to be aware of their limited life span. Some
researchers think that awareness of death influences experiences of
anxiety from the time that a person is old enough to understand
death.
Symptoms of anxiety
In order to understand the diagnosis and
treatment of anxiety, it is helpful to have a basic understanding of
its symptoms.
SOMATIC
The somatic or physical symptoms of anxiety
include headaches, dizziness or lightheadedness, nausea and/or
vomiting, diarrhea, tingling, pale complexion, sweating, numbness,
difficulty in breathing, and sensations of tightness in the chest,
neck, shoulders, or hands. These symptoms are produced by the
hormonal, muscular, and cardiovascular reactions involved in the
fight-or-flight reaction.
BEHAVIORAL
Behavioral symptoms of anxiety include pacing,
trembling, general restlessness, hyperventilation, pressured speech,
hand wringing, or finger tapping.
COGNITIVE
Cognitive symptoms of anxiety include recurrent
or obsessive thoughts, feelings of doom, morbid or fear-inducing
thoughts or ideas, and confusion, or inability to concentrate.
EMOTIONAL
Feeling states associated with anxiety include
tension or nervousness, feeling "hyper" or "keyed up," and feelings
of unreality, panic, or terror.
DEFENSE MECHANISMS
In psychoanalytic theory, the symptoms of anxiety
in humans may arise from or activate a number of unconscious defense
mechanisms. Because of these defenses, it is possible for a person
to be anxious without being consciously aware of it or appearing
anxious to others. These psychological defenses include:
- Repression. The person pushes anxious thoughts or ideas out of
conscious awareness.
- Displacement. Anxiety from one source is attached to a
different object or event. Phobias are an example of the mechanism
of displacement in psychoanalytic theory.
- Rationalization. The person justifies the anxious feelings by
saying that any normal person would feel anxious in their
situation.
- Somatization. The anxiety emerges in the form of physical
complaints and illnesses, such as recurrent headaches, stomach
upsets, or muscle and joint pain.
- Delusion formation. The person converts anxious feelings into
conspiracy theories or similar ideas without reality testing.
Delusion formation can involve groups as well as individuals.
Other theorists attribute some drug addiction to
the desire to relieve symptoms of anxiety. Most addictions, they
argue, originate in the use of mood-altering substances or behaviors
to "medicate" anxious feelings. |