Low-dose thyrotropin-releasing hormone effects in cognitively impaired alcoholics

The cognitive effects of a low dose of thyrotropin-releasing hormone (TRH) (2.0 mg, IV) were evaluated in 18 chronic alcoholic patients who exhibited memory dysfunction secondary to chronic alcohol abuse. The study used a double-blind crossover design that compared cognitive functions in patients with 2.0 mg of TRH IV as compared with a placebo. TRH was chosen because of its ability to enhance cholinergic transmission. Only minimal effects were seen with TRH. Patients with a shorter duration of alcohol use (mean of 16 years) performed significantly better with TRH as compared with placebo on a test involving verbal learning and memory. Those with a more chronic history of alcohol abuse (mean of 27 years) did not show such a response. All of the subjects showed cardiovascular response to TRH. Factors that may have contributed to the results of our study are discussed. It is our impression that future studies evaluating the cognitive effects of TRH in chronic alcoholics need to include an evaluation of the functional activity of TRH in the brain.