A controlled study of folic acid treatment in three fragile X syndrome males.

Three fragile X syndrome males were given 10 mg folic acid daily in a multiple-baseline, placebo study. Objective measures of memory skills, compliance, and behavioral appropriateness were taken during baseline, placebo, and treatment conditions. No change was evident in these variables during the drug trial. Thus, the findings shed doubt on the effectiveness of folic acid in increasing intellectual functioning or reducing behavior problems in individuals with fragile X syndrome. These results underscore the importance of operationally defined variables, double-blind observation and placebo treatment in elucidating the effects of folic acid.