ABSTRACT: The present study investigated the usefulness of a combination of Panax ginseng, vitamins and minerals in reducing fatigue-induced deficits to cognitive functionand mood. A shift-work model was developed in which nurses were repeatedly evaluated on a variety of cognitive tests and questionnaires immediately prior to undertakinga three-night shift and then again immediately afterwards.
On the day before the shift thirty nurses performed a selection of tests from the Cognitive Drug Research (CDR) computerized assessment system, as well as Bond-Lader moodand alertness scales at 0800, 1200, 1400 and 1600 hours. They also completed the Chalder fatigue scale once during this time. On the day immediately following the three-night shift, they returned directly to the laboratory and underwent an identical schedule of testing. The nurses were then assigned randomly to receive either the combination orplacebo for the next twelve weeks in a double-blind, parallel group design. The shift model was then repeated six and twelve weeks later using exactly the same schedule of assessments.
To confirm that the shift model was effective in impairing cognitive function and inducing fatigue, the data for the shift model run prior to randomisation wereinitially evaluated. The three-day shift resulted in significant declines in both speed and accuracy of attention, and the ability to store and retrieve information from memory.Deficits to self-rated calmness and contentment were also identified. In addition, increased levels of fatigue were seen on the Chalder fatigue scale.
This shift-induced deficit was then used as the major study outcome. The pre-study deficitwas used as a baseline, and the deficits measured at weeks 6 and 12 were adjusted to form 'change from baseline shift deficits'. These adjusted scores were then contrastedbetween the two groups at six and twelve weeks.
On the performance assessments, it was found that the combination reduced the deficits resulting from the three-day shifton the Quality of Memory, these effects being significant at the first three time assessments at week 12.