Comorbidity and the Treatment of GAD
GAD is often accompanied by other concurrent psychiatric dis-orders, specifically anxiety and mood disorders. The presence of these comorbid conditions may reflect more severe loading for psychopathology, and may have important implications on the course and treatment response of the primary disorder. In the National Comorbidity Survey, more patients with comorbidity experienced interference with daily activities than did patients with pure GAD (Wittchen et al., 1994). The presence of a comor-bid anxiety disorder and major depressive disorder is frequently associated with a poorer overall outcome than for patients with a single psychiatric disorder (Kessler et al., 1999). Currently, there are treatment options that can target both GAD and major de-pressive disorder simultaneously. The use of SSRIs and the SNRI venlafaxine is recommended as the first-line treatment for co-morbid GAD and depression.
Social anxiety disorder frequently complicates the course GAD takes. With the recent data indicating that the SSRIs such as sertraline and paroxetine are effective in the treatment of so-cial anxiety, these agents may be useful in the treatment of co-morbid social anxiety disorder and GAD. The benzodiazepines that have been established as effective in the treatment of patients with GAD also appear to be effective in the treatment of patients with social anxiety disorder. Thus, these agents (considering the caveats associated with their use described earlier) may have a therapeutic role in patients with GAD and coexisting social pho-bia. Finally, patients with GAD and concurrent panic disorder or panic attacks may be effectively treated with SSRIs, TCAs and benzodiazepines. However, buspirone is probably ineffective in the treatment of panic disorder.
Concurrent alcohol and substance abuse tend to confuse the clinical picture of GAD and can interfere with the thera-peutic efforts. Additionally, symptoms associated with alcohol withdrawal or other sedative–hypnotics may mimic the under-lying anxiety disorder. If a substance abuse problem exists, the clinician and the patient should take the necessary steps to discontinue the use of the abused substance. This may well in-clude specific substance abuse treatment. Specifically, the need for detoxification should be assessed and discussed with the pa-tient. Following cessation of substance abuse the patient’s symp-tomatology should be reevaluated. The use of benzodiazepines in these patients may be contraindicated, and alternative treat-ments with SSRIs, SNRIs, TCAs, buspirone, or gabapentin may be needed.