Rhode Island and Massachusetts researchers found that color of the liquor did not matter as the level of brain impairment was the same after consuming any kind of liquor. A study stated that intoxication’s effect remained even after the booze was out of the blood.

"People will be impaired the morning after even after the alcohol leaves the system," Dr Damaris Rohsenow of the Brown University Center for Alcohol and Addiction Studies in Providence, Rhode Island noted.

The results were conclude after looking at the effects of heavy drinking on 95 young adults aged 21 to 33. The subjects were put to trial for two nights at the Boston test facility. One night they were given alcohol which was either vodka or bourbon mixed in cola and the other night they were given an excuse.

Previous research stated that a hangover usually gets over within a few hours of waking. The study however did not show the duration of impairment. Rohsenow said, "It's likely that the performance effects probably lift within a few hours."

This study also proved the earlier finding that the higher the impurities the lousier a drinker was likely to feel the next day wrong as impairment was the same. This was proved as impairment among people who had bourbon and vodka was the same. The hangover after having bourbon however was worse. Therefore, after a night of heavy drinking it is better to avoid driving even the next morning, researchers said.