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Anxiety Disorders: Future
Directions for Research and Treatment
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Chapter 2
Overview of the Anxiety Disorders
1. What are the Anxiety Disorders?
The anxiety disorders are a group of psychological problems whose key
features include excessive anxiety, fear, worry, avoidance, and compulsive
rituals. The most prevalent anxiety disorders listed in the Diagnostic
and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; American
Psychiatric Association, 1994) include panic disorder with and without
agoraphobia (PDA and PD, respectively), social phobia, specific phobia,
obsessive- compulsive disorder (OCD), generalized anxiety disorder (GAD),
and posttraumatic stress disorder (PTSD). These disorders are the subject
of this review. Other relevant disorders not discussed here include acute
stress disorder (similar to PTSD, except with a shorter duration), anxiety
disorder due to a general medical condition, substance-induced anxiety
disorder, agoraphobia without a history of panic disorder, and anxiety
disorder not otherwise specified. Very little research is available with
respect to these disorders.
a. Panic Disorder with (PDA) and without (PD) Agoraphobia
The main features of PD and PDA are recurrent unexpected panic attacks
(i.e., panic attacks occurring out of the blue, without any obvious situational
trigger), concern about having additional attacks, worry about the consequences
of the attacks, and/or a significant change in behaviour as a result of
the attacks. When the symptoms of PD lead to avoidance of situations in
which escape might be difficult or help might be unavailable in the event
of a panic attack, the individual is said to have agoraphobia, which may
include avoidance of such situations as driving, using public transportation,
travelling, being alone, being in crowds, and shopping.
b. Obsessive-Compulsive Disorder (OCD)
OCD is defined by the presence of obsessions (i.e., recurrent and intrusive
thoughts, images, or urges that cause marked anxiety) and/or compulsions
(i.e., repetitive behaviours or mental acts that are performed to reduce
the anxiety generated by one's obsessions). Typical obsessions concern
contamination, doubting, and disturbing sexual or religious thoughts.
Typical compulsions include washing, checking, ordering things, and counting.
To meet criteria for OCD, the obsessions or compulsions must be time-consuming
or distressing.
c. Social Phobia
Social phobia is an excessive or unrealistic fear of social or performance
situations. Typical situations feared or avoided by individuals with social
phobia include parties, meetings, eating in front of others, writing in
front of others, public speaking, conversations, meeting new people, and
other related situations. In social phobia, the anxiety is not exclusively
related to having the symptoms of another medical or psychiatric condition
noticed by others (e.g., a patient with Parkinson's disease who is
anxious about others noticing a tremor would not be considered to have
social phobia). In addition, the fear must interfere with the individual's
life or be associated with significant distress.
d. Generalized Anxiety Disorder (GAD)
The main feature of GAD is excessive worry occurring more days than not
about a number of different domains or activities (e.g., work, finances,
family, health). The worry must be experienced as difficult to control
and must be associated with at least three of six symptoms which include
restlessness, fatigue, impaired concentration, irritability, muscle tension,
and impaired sleep. To meet criteria for GAD, the worry must not be exclusively
focused on the features of another disorder (e.g., worrying about having
a panic attack, if the individual has PD) and must lead to significant
distress or functional impairment.
e. Specific Phobia
A specific phobia is an excessive or unreasonable fear of an object or
situation, usually associated with avoidance of the feared object or situation.
Examples include phobias of flying, heights, animals, injections, and
blood. The fear must not be related to another disorder (e.g., an individual
with agoraphobia who avoids flying due to the possibility of having a
panic attack), and must be associated with significant distress or functional
impairment.
f. Posttraumatic Stress Disorder (PTSD)
PTSD is a disorder in which an individual experiences a traumatic event
involving actual or threatened death or serious injury to oneself or others
and responds to the event with intense fear, helplessness, or horror.
The fear is associated with symptoms from three categories: (1) re-experiencing
the event (e.g., nightmares, flashbacks, and intrusive memories); (2)
avoidance and emotional numbing (e.g., avoiding talking or thinking about
the trauma); and (3) symptoms of increased arousal (e.g., sleeplessness,
and hypervigilance). PTSD is associated with a duration of at least one
month and symptoms must cause significant distress or functional impairment
to be diagnosed.
2. Prevalence of the Anxiety Disorders
Anxiety disorders are among the most prevalent psychological problems.
Lifetime prevalence rates for experiencing any anxiety disorder, reported
in epidemiological research, vary from 10.4% to 25.1% (Bourdon et al.,
1988); to 11.2% (Bland et al., 1988), to 24.9% (Kessler et al., 1994).
The lifetime prevalence rates for specific anxiety disorders range from
3.5% for panic disorder to 13.3% for social phobia in recent epidemiological
research (Kessler et al., 1994). Appendix 1 contains additional data from
population health surveys, as well as an explanatory note on factors that
could account for the variations in prevalence rates.
According to the Ontario Mental Health Supplement, women are more likely
than men to experience anxiety disorders. The Supplement reported that
the one-year prevalence rate for anxiety disorders was 9% for men and
16% for women (Ontario Ministry of Health, 1994) in the twelve months
preceding the survey.
3. Comorbidity
Most individuals with anxiety disorders have another mental health problem.
In a 1990 study, Sanderson, Di Nardo, Rapee and Barlow found that 70%
of individuals with a principal anxiety disorder diagnosis met criteria
for an additional Axis I disorder, often another anxiety disorder. Specific
and social phobias were the most common additional diagnoses, affecting
about a third of the sample. A third of individuals with principal anxiety
disorder diagnoses met criteria for depressive mood disorder (i.e., major
depression or dysthymic disorder). The frequency of additional diagnoses
differed across the anxiety disorders. Percentages of individuals who
met criteria for one or more additional disorders were 69% for panic disorder
with and without agoraphobia (PDA and PD, respectively), 58% for social
phobia, 81% for generalized anxiety disorder (GAD), 53% for specific phobias,
and 83% for obsessive-compulsive disorder (OCD).
Several studies have shown that alcohol and substance abuse are associated
with anxiety disorders, particularly for individuals with social phobia
and PDA (Cox, Norton, Swinson, and Endler, 1990; Kushner, Sher, and Beitman,
1990). Anxiety disorders, particularly social phobia and GAD, are often
also associated with personality disorders (Sanderson, Beck, and Betz,
1991; Stein, Hollander, and Skodol, 1993). A recent study, based on findings
from the 1984 Epidemiologic Catchment Area Survey, suggests that bipolar
disorder may be associated with anxiety disorders (Chen and Dilsaver,
1995).
A number of studies have examined the impact of treatment for one disorder
on comorbid conditions. Fava, Zielezny, Luria, and Canestrari (1988) found
that behavioural treatment of agoraphobia led to changes in comorbid obsessive-compulsive
symptoms. Similarly, Brown, Antony, and Barlow (1995) found that patients
with PD who underwent CBT experienced a decrease in comorbid conditions.
Comorbidity at pre-treatment was not predictive of treatment outcome.
Comorbidity patterns could have possible preventive implications. For
example, van Ameringen, Mancini, Styan and Donison (1991) found that social
phobia predated mood disorders in 81.7% of cases and predated other anxiety
disorders in 62.7% of cases among individuals with social phobia and a
comorbid condition.
4. Risk Factors1
According to the Mental Health Supplement of the Ontario Health Survey
(Ontario Ministry of Health, 1994), risk factors and socio-demographic
variables associated with anxiety disorders include surviving severe abuse,
parental mental disorder, low income, and being on public assistance.
These were also risk factors for other mental disorders listed in the
report, including mood disorders, substance abuse, and antisocial behaviour.
The Supplement did not examine risk factors for particular anxiety disorders.
Family history of anxiety places individuals at risk for developing an
anxiety disorder. A number of studies have shown that each of the anxiety
disorders tends to run in families, and there is evidence that the relationship
among anxiety disorders in different family members may be genetically
mediated to some extent (Fyer, Mannuzza, Chapman, Martin, and Klein, 1995;
Kendler, Neale, Kessler, Heath, and Eaves, 1992; MacDonald and Murray,
1994; Pauls, Alsobrook, Goodman, Rasmussen, and Leckman, 1995). Parental
behaviour (e.g., a tendency to be overprotective, less affectionate, and
more controlling) appears to be associated with the development of anxiety
disorders, particularly panic disorder without agoraphobia (Gerlsma, Emmelkamp
and Arrindell, 1990; Silove, Parker, Hadzi-Pavlovic, Manicavasagar, and
Blazczynski, 1991). This latter finding could have implications for preventive
interventions.
Risk factors have been identified for some of the individual anxiety
disorders as follows:
- Panic disorder with and without agoraphobia: stressful life
events, perceived negative impact of stressful events, anticipation
of a major life event, substance use, anxiety in childhood, parental
behaviour (e.g. a tendency to be overprotective) age (with the disorder
being more common in those under 65 years of age), and being female
(Faravelli and Pallanti, 1989; Roy-Byrne, Geraci and, Uhde, 1986; Pollard,
Pollard, and Corn, 1989; Kushner et al., 1990; Roy-Byrne and Uhde, 1988;
Aronson and Craig, 1986; Keyl and Eaton, 1990; Angst and Vollrath, 1991);
- Social phobia: childhood history of separation, shyness in
childhood, infrequent dating, parental behaviour (e.g., discouragement
of socializing), and traumatic events (Bruch and Heimberg, 1994; Bruch,
1989; Antony and Barlow, in press);
- Generalized anxiety disorder: anxiety in childhood and being
female (Angst and Vollrath, 1991; Aronson and Logue, 1987);
- Specific phobia: being female, and experiencing traumatic events
(Antony and Barlow, in press); and
- Posttraumatic stress disorder (PTSD): (according to the definition
of PTSD) experiencing a traumatic event.
It should be noted that not all individuals who experience these risk
factors develop anxiety disorders. For example, many individuals experience
traumatic events and do not develop PTSD or phobic disorders. Researchers
are investigating whether mediating variables, such as social support
following the event or biological predispositions, may play a role.
5. Health Care Utilization and Economic Costs
Data on the direct and indirect costs of anxiety disorders to the Canadian
economy remain to be investigated. American data, however, provide some
information. Simon et al. (1995) investigated health care costs associated
with anxiety disorders and depressive disorders among persons attending
three primary care clinics in a health maintenance organization in Seattle
(Washington). Patients with a DSM-III-R anxiety or depressive disorder
were compared to patients without significant mood or anxiety symptoms.
Those with anxiety or depressive disorders cost an average of $2390 ($US)
for a six-month baseline period, compared to $1397 ($US) for those without
anxiety or depressive diagnoses. Other studies show that anxiety disorders
are also associated with lost productivity in the workplace (Salvador-Carulla
et al., 1995).
Evidence suggests that persons with anxiety disorders have more frequent
contact with the health care system than does the general population (Siegel
et al., 1990; Leon et al., 1995; Swinson et al., 1992). These persons
tend to seek help from the general health care system, as opposed to the
mental health care system (Pollard, Henderson, Frank, and Margolis, 1989;
Leon et al., 1995). Swinson et al. (1992) indicate that outside of specialized
anxiety disorders clinics, appropriate diagnosis and empirically validated
treatments may not be provided to patients in either the health and mental
health care systems. This is discussed in the following chapter.
1. Although this report does not focus
on anxiety disorders induced by a general medical condition or by a substance,
it is recognized that individuals may experience anxiety as a result of
a physical illness (e.g., hyperthyroidism) or drug use (illicit, prescription,
or over-the-counter medications).
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