Pilot study of lorazepam and tiagabine effects on sleep, motor learning, and impulsivity in cocaine abstinence.

OBJECTIVES

To test the effects of mechanistically different GABA modulating agents on the disrupted sleep and cognitive function associated with abstinence from cocaine.

METHODS

We examined the effects of lorazepam and tiagabine on polysomnographically measured sleep and cognition in six cocaine dependent persons. Participants were studied during the first and second week of controlled abstinence following intravenous, laboratory cocaine administration.

RESULTS

Lorazepam and tiagabine decreased sleep latency, but whereas lorazepam markedly increased light sleep, tiagabine caused a dramatic shift toward slow-wave sleep. Despite increasing total sleep time, lorazepam impaired sleep dependent learning and increased next day impulsivity.

CONCLUSIONS

These results introduce the possibility of different, sleep-related cognitive effects of mechanistically distinct GABAergic sedative hypnotics.