Abnormal Psychology

Clinical Diagnosis and Assessment 85

can help reduce symptoms of irritable bowel syndrome, a medical disorder marked

by intestinal cramping, bloating, and diarrhea (Blanchard et al., 2006; Whitehead,

2006). Even so, this does not justify including a medical disorder in the DSM.

Social Factors are Deemphasized

Perhaps because DSM-IV-TR does not generally address etio-

logical factors (the causes of a disorder), it does not explicitly

recognize social factors that contribute to disorders (as opposed

to the listing of current psychosocial problems on Axis IV).

DSM-IV-TR states that its diagnoses are not supposed to apply

to confl icts between an individual and society, but rather to con-

fl icts within an individual. However, this distinction is often dif-

fi cult to make (Caplan, 1995). For instance, people can become

depressed in response to a variety of social stressors: after losing

their jobs, after they are exposed to systematic discrimination,

after emigrating from their native country, or after experiencing

other social and societal confl icts.

Comorbidity is Common

About half of the people who are diagnosed with a DSM-IV-TR disorder have

at least one additional disorder; that is, they exhibit comorbidity (Kessler et al.,

2005). This raises the question of whether the disorders in DSM-IV-TR describe

unique clusters of symptoms. For instance, half of the people who are clinically

depressed—that is, whose depression meets the criteria for the DSM-IV-TR disor-

dermajor depressive disorder—also have an anxiety disorder (Kessler et al., 2003).

Such a high rate of comorbidity suggests that, for a signifi cant number of people,

the two DSM-IV-TR disorders may represent different facets of the same underlying

problem. This possibility raises questions about validity and makes DSM-IV-TR di-

agnoses less useful to clinicians and researchers.

Overlooks Commonalities Across Diagnostic Categories

The structure of DSM-IV-TR makes it diffi cult for researchers to identify common-

alities that underlie disorders across the 17 categories. Such commonalities arise

either when particular disorders are frequently comorbid—as is common with de-

pression and anxiety—or when various disorders have some symptoms in common.

In either case, commonly comorbid disorders may be better classifi ed as different

expressions of the same core problem, rather than the way DSM-IV-TR does—as

completely separate disorders.

For example, many emotional and behavioral problems can be categorized

as hinging on either overcontrol or undercontrol; such problems often begin in

childhood and persist into adulthood. Problems that involve overcontrol are

referred to as internalizingproblems because they are largely characterized by

the internal experiences associated with them; examples include depression and

various types of anxiety. Problems that involve undercontrol are referred to as

externalizing problems because they are largely characterized by their effects on

others and on the environment; examples include aggression and disruptive be-

haviors, such as occur in attention-defi cit/hyperactivity disorder and delinquency.

Not all emotional or behavioral problems fi t into these categories, however, and

an “other” category was created to include eating disorders and learning disor-

ders (Achenbach, McConaughy, & Howell, 1987; Kazdin & Weisz, 1998). But

DSM-IV-TR doesn’t provide any way to classify or group disorders that involve

internalizing or externalizing problems, making it more challenging for research-

ers to identify commonalities.

Although the criticisms of DSM-IV-TR have merit, the clinical chapters of

this book (Chapters 6–15) are generally organized according to DSM-IV-TR cat-

egories and criteria. DSM-IV-TR is by far the most widely used classifi cation

system for diagnosing psychological disorders, and it will no doubt provide the

foundation for a revised edition in the future.

One criticism of DSM-IV-TR is that social factors

that contribute to psychological disorders—such

as being laid off from work—are not incorporated

into the diagnosis (Caplan, 1995).

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