Abstract

OBJECTIVE:

Ginseng is a popular, commercially available dietary supplement that is purported to have a number of psychological benefits. The purpose of this study was to examine these claims, with specific reference to ginseng's effects on affect and mood.

DESIGN:

Prospective, double-blind, placebo-controlled, randomized clinical trial.

PARTICIPANTS/SETTING:

Eighty-three adults (40 women, 43 men) participated in this study (mean age = 25.7 year). Participants were recruited from within a university community and at area health clubs.

INTERVENTION:

Participants were randomly assigned to one of three experimental conditions: placebo (lactose), 200 mg ginseng, or 400 mg ginseng. The ginseng preparation used in this study consisted of the Panax ginseng C A Meyer concentrate G115 in capsular format. Each participant was given a 60-day allotment of their respective supplement along with written instructions about the proper intake and storage of the capsules during the 8-week study period.

MAIN OUTCOME MEASURES:

Positive affect, negative affect, and total mood disturbance. Measures were obtained pre- and post-intervention.

STATISTICAL ANALYSES PERFORMED:

Repeated measures multivariate analysis of variance was used. Because there were three dependent variables, and in an effort to minimize the experimentwise-error rate, alpha was adjusted using the Bonferroni technique (i.e., P < .05/3 = P < .016).

RESULTS:

Ginseng supplementation had no effect on positive affect, negative affect, or total mood disturbance (all P > .016).

CONCLUSION:

The present findings do not support claims that chronic ginseng supplementation--at either its clinically recommended level or at twice that level--enhances affect or mood in healthy young adults.