Sodium valproate and cognitive functioning in normal volunteers.

1 The effects of sodium valproate on the performance of a series of psychological tests and mood was studied. 2 Ten healthy male volunteers received sodium valproate and placebo, each for a period of 2 weeks, in a double‐blind cross‐over design. Dosage of sodium valproate was increased to 800 mg/day in the first week and to 1 g/day in the second week of treatment. 3 Psychological testing took place on three occasions, before and on completion of each of the two treatment periods. 4 The few significant differences between drug and placebo conditions indicated impairment on sodium valproate. 5 The findings are discussed in relation to those from a similarly designed study of the anticonvulsant phenytoin. Implications for epilepsy are also considered.