A new review of studies suggests that a nightcap before bed probably isn't a good idea. Scientists at the London Sleep Centre find that alcohol may help you drift off, but it can also disrupt your sleep cycle.

Alcohol shortens the time it takes to fall asleep and can quickly send you off into deep sleep, but it also reduces the most satisfying type of sleep, REM sleep, which is where dreams occur.

Also, people can become dependent on alcohol for sleep, researchers say, and alcohol can turn non-snorers into snorers, and snorers into people with sleep apnea.

Dr. Irshaad Ebrahim, medical director at the London Sleep Centre and coauthor of the review, and his team looked at more than 100 studies on sleep, analyzing 20 in detail as to how alcohol alters sleep.

The findings will appear in the April 2013 issue of Alcoholism: Clinical & Experimental Research.

If you're using alcohol as a sleep aid, WebMD offers a few healthier alternatives, such as getting regular exercise, avoiding caffeine in the evening, and establishing regular waking and sleeping times. Also keep your bedroom at a cool temperature and reserve your bed for sleeping and sex only.