Cocaine effects in sleep-deprived humans

Area of Science:

• Neuroscience
• Pharmacology
• Human Physiology

Background:

• Sleep deprivation significantly impairs cognitive functions, including reaction time.
• Cocaine is a stimulant known to affect cardiovascular function and cognitive performance.

Purpose of the Study:

• To investigate the effects of inhaled cocaine on cognitive performance and cardiovascular responses following sleep deprivation.
• To assess whether cocaine can mitigate performance deficits induced by sleep loss.

Main Methods:

• Eight healthy volunteers underwent reaction-time and work-output tasks after 24 and 48 hours of sleep deprivation.
• Participants received either inhaled cocaine (96 mg) or a placebo.
• Cardiovascular measures (heart rate) and subjective reports of mood and drug effects were recorded.

Main Results:

• Sleep deprivation impaired reaction-time performance.
• Inhaled cocaine reversed the performance decrements caused by sleep deprivation.
• Cocaine increased heart rate in both non-deprived and sleep-deprived states.
• The cocaine-induced heart rate increase was attenuated after 48 hours of sleep deprivation compared to 24 hours.
• Subjective reports indicated stimulant effects similar to amphetamine, with no immediate post-drug depression, though some rebound effects were observed later.

Conclusions:

• Inhaled cocaine can temporarily restore cognitive performance deficits associated with sleep deprivation.
• Cocaine exerts stimulant effects on heart rate, but this response may be diminished with prolonged sleep loss.
• The acute effects of cocaine do not appear to induce immediate post-drug depression in this context.