Generalized Anxiety Disorder 225
demonstrate different patterns of comorbidity consistent with gender differences in the
prevalence of disorders. In females, comorbidity is largely confined to the anxiety disor-
ders and unipolar depression, whereas in male s, comorbidity is more likely to extend to
the substance use disorders as well.
Functional Consequences of 
Generalized Anxiety Disorder
Excessive worrying impairs the individual’s capa city to do things quickly and efficiently,
whether at home or at work. The worrying takes time and energy; the associated symp-
toms of muscle tension and feeling keyed up or on edge, tiredness,  difficulty concentrat-
ing, and disturbed sleep contri bute to the impairment. Importantly the excessive worrying
may impair the ability of individuals with ge neralized anxiety disorder to encourage con-
fidence in their children.
Generalized anxiety disorder is associated with  significant disability and distress that is
independent of comorbid disorders, and most non-institutionalized adults with the disorder
are moderately to seriously di sabled. Generalized anxiety di sorder accounts for 110 mil-
lion disability days per annum in the U.S. population.
Differential Diagnosis
Anxiety disorder due to another medical condition. The diagnosis of anxiety disorder
associated with another medical condition should be assigned if the individual’s anxiety
and worry are judged, based on history, labora tory findings, or physical examination, to
be a physiological effect of another specific medical condition (e.g., pheochromocytoma,
hyperthyroidism). 
Substance/medication-induced anxiety disorder. A substance/medication-induced
anxiety disorder is distinguished from generaliz ed anxiety disorder by the fact that a sub-