Zolpidem-induced increases in the sedative/intoxicating effects [Pentobarbital, Chlorpromazine, Alcohol Group (PCAG; top)] as well as decreases in the stimulant-like effects [Benzedrine Group (BG; bottom)] as assessed by the ARCI. All values are means ± SEM. Symbols represent significant differences from placebo (p< 0.05) where * is for 5 mg, † is for 10 mg, ‡ is for 20 mg, and ¥ denotes significance for all three doses. Maximum rating scales for PCAG and BG are 15 and 13, respectively; scales have been shortened for illustrative clarity.