Does Modafinil Enhance Cognitive Performance in Young Volunteers Who Are Not Sleep-Deprived?

Abstract

In a double-blind, parallel groups study, 60 healthy student volunteers (29 men and 31 women, aged 19-22 years) were randomly allocated to receive placebo, 100 or 200 mg modafinil. Two hours later, in the early evening, they completed an extensive cognitive battery. The 3 groups did not differ in self-ratings of sleepiness or tiredness before the testing session, and there were no treatment-associated changes in these or in mood ratings during the tests. Modafinil was without effect in several tests of reaction time and attention, but the 200-mg group was faster at simple color naming of dots and performed better than placebo in the Rapid Visual Information Processing test of sustained attention. Modafinil was without effect on spatial working memory, but the 100-mg group performed better in the backward part of the digit span test. Modafinil was without effect on verbal short-term memory (story recall), but 100 mg improved digit span forward, and both doses improved pattern recognition, although this was accompanied by a slowing of response latency in the 200-mg group. There were no significant effects of modafinil compared with placebo in tests of long-term memory, executive function, visuospatial and constructional ability, or category fluency. These results suggest that the benefits of modafinil are not clearly dose-related, and those from 100 mg are limited to the span of immediate verbal recall and short-term visual recognition memory, which is insufficient for it to be considered as a cognitive enhancer in non-sleep-deprived individuals.

Modafinil Attenuates Disruptions in Cognitive Performance During Simulated Night-Shift Work

“…Modafinil also improved performance during day-shift work but to a lesser degree. This observation is in line with other researchers who found that the drug produced limited effects on cognitive performance in healthy, well-rested individuals (eg, Muller et al, 2004;Randall et al, 2004Randall et al, , 2005. By contrast, modafinil produced greater sleep disruptions when participants worked on the day shift than when they worked on the night shift.…”

Modafinil restores memory performance and neural activity impaired by sleep deprivation in mice

“…Thus, modafinil could not be considered as a cognitive enhancer in non sleep-deprived healthy subjects (Randall et al, 2005). On the opposite, previous results of our laboratory obtained on healthy sleepdeprived adults (after a 60-hr sleep deprivation period) showed that modafinil is able to restore the overall psychomotor performance to the non sleep-deprived levels (Lagarde and…”

Pharmacogenetics of Modafinil After Sleep Loss: Catechol-O-Methyltransferase Genotype Modulates Waking Functions But Not Recovery Sleep

“…Low-dose modafinil does not reliably enhance cognitive task performance in non-sleepdeprived subjects (32,33). Similarly, the drug's efficacy to reduce subjective and objective measures of sleepiness after sleep deprivation differs widely among individuals (22).…”