Lithium effects on active and passive avoidance behavior in the rat.

Lithium chloride reduced the rate of acquisition of a passive-avoidance response and decreased the rats' reaction to the shock delivery. Acquisition of an active-avoidance response was unimpaired by lithium, although lithium-administered rats responded predominantly to the cue stimulus, making significantly fewer precue avoidance responses than did controls. Lithium's efficacy in the treatment of manic disorders may, therefore, be the result of a decrease in the individual's reactivity to low-intensity stimulation.