Changes in learning, memory, and mood during lithium treatment

Abstract

In a double-blind study the effects of a 14-day Li medication (dosage: 24 mval[gram-equivalent]/day to 36 mval/day) were investigated. The subjects were 24 healthy male volunteers. The effect of Li on their mood, ability to learn nouns, and memory of the words learned was measured after 2 h and 14 days. Despite a relatively low mean plasma Li level on the 14th day (0.54 .+-. 0.15 mM), the Li volunteers assessed themselves after 2 wk of treatment as significantly less relaxed, less active, less sociably involved, more bored and more tired than the placebo group. The Li group showed only a slight impairment of performance compared with the placebo groups. There was a significant difference in free recall over 2 wk: the Li group remembered fewer words than the placebo group. Additional motivation of free recall over 2 h was ineffective. It is discussed whether Li changes spontaneous initial action and thereby the will to act. This could be interpreted as a change in the production of the characteristics of experience and behavior.