I'm fairly early in my meditation practice (even 25 minutes can be difficult some days), but I have read some scriptures (mostly Theravada as of late, we're reading the Dhammapada in the philosophy course I'm taking) and almost all of them tend to be pretty specific that alcohol and drugs negatively affect the practice. I don't really want to get into the drugs issue as I could write an essay on that (a la Rick Strassman), but I do often wonder about alcohol.
There is no denying that getting blitzed makes you "less mindful" of your surroundings. It is also (in my own experience) very addictive, and can serve as an emotional escape when you're feeling particularly depressed.
In my own searches I found article by Ted Rose: http://www.beliefnet.com/Faiths/Buddhis ... y-Sip.aspx" onclick="window.open(this.href);return false;
It talks about the practice of "mindful drinking". To quote the article.
How do you feel about this? Do you, as a lay Buddhist, indulge in some "mindful" (or less-than-mindful) drinking? Or do you feel that prohibitions against drinking only applies to those pursuing a monastic path?Here's the basic idea: Once a meditator has developed basic Buddhist discipline (known as Hinayana training) and adopted the intention to dedicate his or her life to benefit others (the Mahayana view) the practitioner is ready to incorporate Vajrayana teachings, where the simple prohibitions outlined in the Sutras are re-evaluated. When a meditator reaches this point, which often takes a number years in the Shambhala tradition, a dangerous substance like alcohol is viewed as a potential aide for the practitioner. Within the context of strong discipline and clear intention, alcohol holds the possibility of no longer acting as a conventional escape, but instead being a tool for loosening the subtle clinging of ego.
"Imagine you are enjoying a picnic in a beautiful spot with your lover," says McKeever. "You want for nothing in this situation." If you choose to drink at this moment, theoretically, you have no reason to overdo it. You'll drink just enough to relax, to appreciate your situation and, as McKeever puts it, "to help your ego go to sleep."
I feel that if one is non-attached and mindful as in the example given, then there should be no problem in consuming alcohol. Going to extremes (ie. drinking a bottle of whiskey every day for a week while also consuming 12 cups of coffee daily and sleeping four hours a night... Not that I've done that. Recently.) is when problems arise. When I have a beer (singular) with lunch or on a date I feel relaxed and no less "aware" than I was before, but I've seen fellow students get so drunk that they don't know where they are and some have even soiled themselves.
Drugs are a whole other topic, and I have a few papers to write in the interim.