Carbamazepine: Treatment of Affective Illness and Anxiety Syndromes

Abstract

Several lines of evidence suggest that carbamazepine (Tegretol), an anticonvulsant effective in the treatment of major motor and psychomotor seizures, might represent a new type of drug useful in the treatment of patients with affective illness. While the structure of carbamazepine is similar to imipramine and chlorpromazine, its mechanism of action appears to be different from that of either classic tricyclic or neuroleptic medications^1–3. Dalby⁴ reviewed the research of 40 studies which together included 2500 seizure patients treated with carbamazepine. In most of these studies, there was an improvement in mood and behavior. In addition, Dalby⁵ himself reported that symptoms of episodic depression improved in 11 of 18 psychomotor epileptic patients treated with open carbamazepine. The improvement in depression and manic-like behavior with carbamazepine therapy in some cases was not associated with an equally robust control of seizures. Dalby’s⁵ observations suggested that carbamazepine might have psychotropic properties independent of its effects on clinical seizure control. Consistent with this hypothesis, numerous studies have demonstrated carbamazepine^[1]s efficacy in the treatment of neurological syndromes unrelated to a seizure diathesis such as trigeminal, glossopharyngeal, and post-herpetic neuralgias. Furthermore, Takazaki and Hanaoka⁶ and Okuma and colleagues⁷ found that open carbamazepine had positive psychotropic effects in psychiatric patients without overt organic lesions or epilepsy. While carbamazepine’s psychotropic and analgesic properties clearly are not related directly to improved seizure control, its “stabilizing” effects on limbic substrates may be pertinent in this regard.