Comorbidity as a fundamental feature of generalized anxiety disorders: results from the National Comorbidity Study (NCS).
Generalized anxiety disorder (GAD) is a relatively common mental disorder in the general population, afflicting approximately 3% of community residents during their lifetime. It is not a benign condition, since significantly increased disability and dysfunction are found in GAD subjects compared to non-GAD subjects. For decades GAD has frequently been observed in the context of other mental and substance abuse disorders. Initially the weight of clinical opinion indicated that GAD was a residual disease which should only be diagnosed when other mental disorders are not present. More recently there has been a growing recognition that comorbidity is a fundamental characteristic of the course and nature of GAD. In a series of secondary analyses conducted in subjects in the National Comorbidity Study database, we found that 8 out of 10 subjects with lifetime GAD also had a comorbid mood disorder during their lifetime. We found unipolar disorders to be four times more common in GAD than bipolar disorders (67% vs. 17%), providing indirect support for the previously reported observation that GAD and major depression may share a common genetic diathesis. In addition, our analyses support the conclusion that when comorbid mood disorders are present in GAD, a significant increase in associated disability and dysfunction is also found. Thus this comorbid relationship has important implications for clinical course and outcome.
Judd
L L
LL
Department of Psychiatry, University of California San Diego, USA.
Kessler
R C
RC
Paulus
M P
MP
Zeller
P V
PV
Wittchen
H U
HU
Kunovac
J L
JL
D000293:Adolescent; D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D014481:United States / Q000453:epidemiology