As you gear up to celebrate the holidays, you might want to keep the results of a new study in mind. Smoking actually increases the odds that you will experience terrible hangouver after a night of merrymaking.

To look at this relationship in more detail, researchers polled 113 college students about their drinking and smoking habits over a period of eight weeks. Every day the students logged how much alcohol they consumed and how many cigarettes they smoked while they drank. They also indicated how hung over they felt the day after consuming alcohol.

‘After the same number of drinks, people who smoke more that day are more likely to have a hangover and have more intense hangovers,’ says researcher Damaris J. Rohsenow.

The more the kids smoked during a night of heavy drinking, the more likely they were to experience a hangover the next day, especially a more intense hangover. The team controlled for variation in the amount of alcohol consumed, and other individual factors like drug use and sex.

“At the same number of drinks, people who smoke more that day are more likely to have a hangover and have more intense hangovers,” said researcher Damaris J. Rohsenow, in a news release. The reason for this isn’t completely clear, but it is known that nicotine and alcohol work in tandem on the brain, and, when used at the same time, appear to increase the levels of the “feel good” neurotransmitter dopamine.

Previous studies have shown that smoking can increase the amount of damage done to the brain by long-term heavy drinking. The physiological mechanisms for the smoking-hangover connection aren’t quite clear at this time – it’s likewise unknown whether hangovers themselves inflict any kind of long-term damage on the brain.

What is clear is that hangovers can reduce a person’s attention and reaction time in the short-term. So refraining from driving or from doing work that requires attention to detail or might put a person’s safety at risk is probably wise. Of course, not drinking to the point where a hangover is a likelihood is also a good idea. And smoking, whether you’re drinking or not, is always a bad idea – so take advantage of the New Year that’s approaching and make a date with yourself to quit.

The research was carried out at Brown University and published in the Journal of Studies on Alcohol and Drugs.