The GABA uptake inhibitor tiagabine promotes slow wave sleep in normal elderly subjects

Aging is associated with a dramatic decrease in slow wave sleep (SWS) and sleep consolidation. Previous studies revealed that various GABA(A) agonists and the GABA uptake inhibitor tiagabine augment slow frequency components in the EEG within non-REM sleep, and thus promote deep sleep in young individuals and/or rats. In the present double-blind, placebo-controlled study, we assessed the effect of a single oral dose of 5 mg tiagabine on nocturnal sleep in ten healthy elderly volunteers (6 females). During the placebo night the subjects displayed a low sleep efficiency, due to high amounts of intermittent wakefulness, and little SWS. Tiagabine significantly increased sleep efficiency, tendentially decreased wakefulness and prominently increased both SWS and low-frequency activity in the EEG within non-REM sleep. The present findings demonstrate that tiagabine increases sleep quality in aged subjects. Moreover, the effects of tiagabine closely match those evoked by the GABA(A) agonist gaboxadol in young subjects and indicate that such compounds may have prospects in the treatment of sleep disturbances, particularly of those commonly occurring in the elderly.