Biological Basis of Generalized Anxiety Disorder

Despite the considerable revisions to diagnostic criteria, recent data indicate that generalized anxietydisorder (GAD) is one of the most common anxiety disorders. Growing evidence also indicatesthat GAD is a serious illness, which frequently causes moderate impairment and often requires prolongedtreatment. Thus, investigation of the biological correlates of GAD may be helpful in the developmentof effective treatments for this disorder. Recent data suggest possible abnormalities in theregulatory mechanisms of several important biological components in GAD patients. Maladaptive responsesto stressful stimuli have been observed in the locus-ceruleus-norepinephrine-sympathetic nervoussystem, the hypothalamic-pituitary-adrenocortical axis, and the cholecystotin system. Abnormalitiesin other important CNS modulators, such as 5-HT and gamma-aminobutyric acid, may alsobe involved in the biology of GAD. In the following article, the authors will review the existing informationregarding these potential biological abnormalities in GAD.