The Role of Anticonvulsant Drugs in Anxiety Disorders: A Critical Review of the Evidence
Antiepileptic drugs (AEDs) have been successfully used in the treatment of mood disturbances, leading clinicians and researchers to investigate their use in other psychiatric disorders. This article reviews the literature about the potential efficacy of AEDs in anxiety disorders. An updated MEDLINE search (January 1970 to September 2006) using the terms "panic disorder," "agoraphobia," "posttraumatic stress disorder," "obsessive-compulsive disorder," "generalized anxiety disorder," "social phobia," "phobia," "carbamazepine," "phenobarbital," "phenytoin," "valproate," "lamotrigine," "topiramate," "vigabatrin," "tiagabine," "gabapentin," "levetiracetam," and "pregabalin" showed more than 70 articles and 38 published studies. Only articles published in English were reviewed. We have assigned level 1 of evidence to meta-analysis and replicated randomized controlled trials, level 2 to at least 1 randomized controlled trial, level 3 to uncontrolled trials with 10 or more subjects, and level 4 to anecdotal case reports. The strongest evidence has been demonstrated for pregabalin in social phobia and generalized anxiety disorder, lamotrigine in posttraumatic stress disorder, and gabapentin in social anxiety. The available data about gabapentin in panic disorder are somewhat mixed, and more definitive conclusion would require additional studies. This review suggests that AEDs can be an alternative treatment in some anxiety disorders. Further investigation is needed to determine in what circumstances they should be used in individuals who are partially responsive or nonresponsive to conventional therapy.