Restoration of risk-propensity during sleep deprivation: caffeine, dextroamphetamine, and modafinil.
BACKGROUND
Sleep deprivation alters risk-related judgments, decision-making, and behavioral control. Stimulant medications are used to restore cognitive performance, but their effects on risk-taking and judgment in sleep-deprived subjects have not been explored.


METHODS
There were 54 healthy adults (29 men, 25 women; age range 18 to 36) who completed a test of cognitive ability and daily measures of risk-taking propensity, including the Brief Sensation Seeking Scale (BSSS), Evaluation of Risks (EVAR) scale, and the Balloon Analog RiskTask (BART). Following 44 h of continuous wakefulness, participants ingested caffeine 600 mg (N = 12), dextroamphetamine 20 mg (N = 16), modafinil 400 mg (N = 12), or a placebo (N = 14) in a double blind manner, and completed risk-taking measures 2 h later (i.e., 0535).


RESULTS
Relative to rested baseline, the placebo group showed a decline in risk-taking as measured by the BSSS (16% decline), EVAR Danger Seeking (32% decline) and Energy (22% decline), and BART (32% decline), consistent with previous reports of the effects of sleep deprivation. Comparisons among drug conditions showed that dextroamphetamine restored risk-taking propensity and risky behavior to baseline levels, an effect that was significantly greater than placebo or caffeine for several indices of risk-taking, but which did not differ from modafinil. Cognitive ability was significantly correlated with changes on some risk-taking indices following stimulant administration.


CONCLUSIONS
Stimulant medications, particularly dextroamphetamine, sustained risk-related attitudes and behavior during continuous wakefulness. The extent to which stimulants restore other aspects of judgment during sleep loss remains to be determined.
Killgore
William D S
WD
Neuroimaging Center, McLean Hospital, Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA. killgore@mclean.harvard.edu
Grugle
Nancy L
NL
Killgore
Desiree B
DB
Leavitt
Brian P
BP
Watlington
George I
GI
McNair
Shanelle
S
Balkin
Thomas J
TJ
D000328:Adult; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D002110:Caffeine / Q000627:therapeutic use*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D003657:Decision Making; D003913:Dextroamphetamine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D007600:Judgment / Q000502:physiology*; D008297:Male; D000077408:Modafinil; D011594:Psychometrics; D012306:Risk; D012309:Risk-Taking; D012892:Sleep Deprivation / Q000150:complications*
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D002110:Caffeine; D000077408:Modafinil; D003913:Dextroamphetamine