Allport, I think Anna was referencing alcohol as a depressant and the issue of depression because one that has depression shouldn't drink alcohol. The potential for increasing one's depression through alcohol use is high. Here's an article that probably explains it better then I can.
Physiological Effects of Alcohol - Role in Depression
Alcohol has been found to lower serotonin and norepinephrine levels.
**"Food and Mood," Natural Medicine Chest, Conquer Depression Without Drugs, Let's Live magazine, Jan. 2000}
"Alcohol is a depressant. People with depression shouldn't drink alcohol", says Sherry Rogers, MD, in her 1997 book on "Depression." She says that studies show that doctors miss diagnosing over 66% of the people who are depressed.
Alcohol temporarily blunts the effects of stress hormones. It typically leaves you feeling worse than ever because it depresses the brain and nervous system. One study looked at people who consumed one drink a day. After three months abstinence, their scores on standard depression inventories improved.
{The Brain, "You Can Control Your Emotional Wellness," USA WEEKEND, Jan. 3, 1999, Jim Thorton, health reporter}
People with manic-depressive disorder should not drink alcohol.
{James F. Balch, MD, newspaper columnist and radio broadcaster, 1990}
Although important for all ages, in older people folic acid deficiency contributes to aging brain processes and increased risk of Alzheimer’s disease and vascular dementia. Depression is also common in those with folate deficiency.
{British Medical Journal, 2002} Andrew Weil, in his Self Healing newsletter (Jan. 2000) tells us alcohol use can lower levels of folic acid. The presence of alcohol hastens the breakdown of antioxidants in the blood, speeding their elimination from the body.
The acute depressant effect of alcohol increases with BAC, and has been measured in terms of its effects on human performance at BACs as low as 0.03.
{“Alcohol Effects on People,” U.S. Department of Transportation (HHTSA), Alcohol and Highway Safety, 2001, Dec. 2002}. Author’s comments: The BAC level of 0.03 can be obtained form one or two alcoholic beverages.
Depression and Alcohol Problems Go Together
When alcohol wears off, you will be more depressed than ever.
{Ann Landers' to readers, Dec. 5, 1993, as well as many other medical sources}
Depression and alcohol problems often go together, but the evidence suggests that in men alcohol use preceded the depression, whereas in women the depression precedes the alcohol use.
{American Journal of Epidemiology, "Study Links Depression and Alcohol Problems," Washington Post Health, Dec. 16, 1997}
Here's the link to where this article may be found -
Facts and Statistics About Depression and Alcohol