Choline chloride effects on memory: correlation with the effects of physostigmine.

Choline chloride (2g q.i.d.) and placebo were admin stered to nine young adults in a placebo-drug-placebo design. Subjects took memory tests at the end of both placebo periods and at the end of the choline period. All nine subjects had participated in a previous study in which 1.0 mg of physostigmine infused over a 1-hour period improved memory performance relative to performance during a saline infusion (Davis et al., 1978b). Choline had no significant efect on average performance either on a test of memory storage or on a test of memory retrieval. However, correlational analysis indicated that subjects who improved most when given physostigmine tended to show slight improvement when given choline. These results suggest that choline does not have substantial effects on memory but that there are small cognitive effects of choline in some subjects.