Hormetic dose-response relationship of lithium on motor cortical excitability

Introduction: Lithium has been widely used for treatment of bipolar disorders for over 50 years. Still, the acute cortical effects of lithium in humans are poorly investigated. This study aimed at investigating the effects of several doses of lithium on corticospinal excitability as measured by transcranial magnetic stimulation (TMS). Methods: Seven healthy, non-smoking right-handed subjects (4 female, mean age, 26 years) participated in this randomized, double-blind, placebo-controlled crossover study. Subjects took one of three single oral doses of lithium (450mg, 900mg, or 1350mg) or placebo in 4 sessions sep…