Linopirdine (DUP 996): Cholinergic treatment of older adults using successive and non-successive tests

The purpose of this study was to examine whether cholinergic treatment of a ge-associated memory impairment with Linopirdine (DUP 996), a derivate of p henylindoline, affects explicit memory, implicit memory, and primary memory . We also assessed cognitive decision making in a reaction time test. Expli cit memory was assessed by face recognition, word recall and a word recogni tion test, being part of a successive test paradigm. Implicit memory was as sessed by primed word fragment completion in the same successive test parad igm. Primary memory was studied by means of digit recall. Thirty-eight elde rly subjects fulfilled the criteria for memory impairment. Four groups of s ubjects were given 10, 20 or 30 mg of DUP 996 or placebo during 4 weeks. A double-blind procedure was applied. No significant treatment effects for re cognition memory and priming were obtained in the successive test paradigm. Analysis of dependence/independence between tests did not show any clear p attern of treatment effects. The other explicit memory tests and the reacti on time test showed no effect with DUP 996. Because of the range of the dif ferent tests used here, the result and the general evidence in other invest igations of the cholinergic depletion among aged people, the conclusion is that DUP 996 does not improve memory performance either in explicit, implic it or primary tests.