The authors found evidence of impaired performance on serial and free recall verbal learning tasks during depression and mania. Treatment with L-dopa and L-tryptophan significantly improved performance on these tasks, while imipramine, lithium carbonate, and alpha-methyl-para-tyrosine treatments had no effect. These results should be taken into account when using psychotherapeutic approaches designed to teach new response patterns to patients with affective disorders.Abstract Teaser