Minimizing the cognitive effects of lithium therapy and electroconvulsive therapy using thyroid hormone

Although electroconvulsive therapy (ECT) and lithium are effective treatments for mood disorders, they are both associated with cognitive side-effects that reduce patient compliance and satisfaction. Because both ECT and lithium have significant impact on the hypothalamic-pituitary-thyroid (HPT) axis, at least some of these side-effects may be associated with alterations in HPT activity. There is evidence that cognitive deficits in patients with bipolar disorder taking lithium are related to diminished thyroid status, but not to serum lithium level. A preliminary study showed that adjunctive use of thyroid hormone significantly improves cognitive functioning in patients taking lithium. An animal study and two double-blind, placebo-controlled clinical studies examining the adjunctive use of thyroid hormone (T3) and ECT have confirmed that T3 significantly protects against ECT-related memory impairment compared to placebo. Taken as a whole, this research suggests that adjunctive use of thyroid hormone has the potential to reduce cognitive side-effects of these important psychiatric treatments.