Cognitive enhancement in Korsakoff's psychosis by clonidine: a comparison with L-dopa and ephedrine.

Each of three catecholamine agonist medications (clonidine, L-dopa, and ephedrine) and placebo were administered for 2-week trials to a group of amnesics with Korsakoff's psychosis following a double-blind, counterbalanced design. During the last 3 days of each treatment, patients were given a battery of neuropsychological tests to determine the effects of the drugs on memory and related cognitive processes. Only clonidine had a significant effect on measures of anterograde amnesia, and this response was restricted to the same psychometric measures that improved with clonidine in an earlier study (McEntee and Mair 1980). Each of the medications affected performance on some measures of attention. None of the treatments had any effect on measures of retrograde amnesia or digit-symbol substitution. There appears to be a significant negative correlation between the amnestic effects of clonidine and the concentration of the primary noradrenergic metabolite in lumbar CSF (as measured prior to the initial drug trial).