Not surprisingly, drugs (including caffeine, alcohol, and nicotine) can greatly affect the quality and quantity of sleep. Here's a breakdown of how each of these drugs may have an effect on your sleep:

Caffeine

Caffeine (technically known as trimethylxanthine) is a stimulant of the central nervous system (CNS), which is composed of your brain and spinal cord. It produces a sensation of alertness and increased energy (it also acts as a diuretic). Some common dietary sources of caffeine include coffee, some teas, soft drinks, and chocolate (click here to view a table of the caffeine content of some common foods). Obviously, such a substance will impact sleep. Consuming caffeine at any point during the day can make it difficult for you to fall and remain asleep, but especially avoid consuming caffeinated food and beverage items within 4-6 hours of going to bed. Click here for more information about the effect of caffeine on sleep.

Alcohol

Contrary to caffeine, alcohol is a CNS depressant, and can make you feel drowsy and even make it easier to fall asleep. However, sleep is interrupted more often and is of a lower quality after consuming alcohol. Also, the effects of alcohol are graded: the more you drink, the worse you'll sleep. Additionally, alcohol will have a stronger effect on someone who is fatigued compared with someone who is well-rested. To get a good night's sleep, avoid alcohol within 2-4 hours before going to sleep. For more information about how alcohol affects sleep, visit the National Institute on Alcohol Abuse & Alcoholism website.

Nicotine

Nicotine is a CNS stimulant. Yet another good reason to quit smoking ...Smokers tend to have poorer quality sleep and wake up more frequently during the night due to withdrawal symptoms.

Sleeping Pills

Sleeping pills are prescribed for transient sleep problems, usually for a period of 2-4 weeks. They tend to be highly addictive and people quickly build up a tolerance to the sleep-promoting effects. Often, it is more useful to address the underlying cause of not being able to sleep in order to avoid using sleeping pills. Some common causes of sleeping difficulties include daytime stress, symptoms of depression and/or anxiety, and environmental factors such as light, noise, or temperature.