Clinical experience indicates that the concurrent use of electroconvulsive therapy (ECT) and some psychoactive drugs is safe. With the exception of caffeine to prolong ECT seizure duration, no agent reliably enhances the efficacy of ECT.Despite the paucity of adequate prospective studies, antipsychotic drugs (including clozapine) may be safely combined with ECT. Furthermore, this combination is probably more effective in relieving psychoses than either treatment alone. Similarly, there is no evidence of an antagonism of efficacy or a loss of safety during the use of ECT and antidepressants, such as tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) or lithium. However, prolongation of seizures may be a concern with a combination of SSRIs and ECT, and enhanced confusion a concern with lithium and ECT.In contrast, benzodiazepines inhibit the efficacy of ECT and, therefore, combined use should be avoided. Where such use is deemed necessary, the administration of flumazenil (a benzodiazepine antagonist) before ECT may be considered. The continued use of other anticonvulsants during ECT depends on their effect on ECT-induced seizure adequacy, which remains ill-defined. There are special risks associated with administering ECT to patients who have therapeutic plasma concentrations of theophylline or lidocaine (lignocaine).During the evaluation of new psychoactive drugs, studies of possible interactions with ECT are rarely performed. Therefore, the data available are inferred from case literature alone. Such data are notoriously deficient, and attention to premarketing testing of such interactions is warranted.