Gabapentin resulted in significantly less PSG wake after sleep onset ( WASO ) compared with placebo on Day 1 ( primary endpoint , mean : 107.0 versus 149.1 min , p 0.001 ) and Day 28 ( 113.6 versus 152.3 min , p = 0.002 ) , and significantly greater total sleep time ( TST ; Day 1 : 347.6 versus 283.9 min ; Day 28 : 335.3 versus 289.1 min ) ( p 0.001 ) .