(dailyRx News) We already know that heavy drinking can lead to depression, and that heavy depression can lead to drinking. But does that mean alcoholism and major depression are always linked?
Not necessarily - but it can be hard to know what the relationship is between the two conditions. Some people may say they drink because they're depressed but the evidence shows they may be more likely to be depressed because they drink.
Therefore a recent study tracked both conditions in men for three decades to find out more about how alcoholism and depression relate to each other.
They found that just under a third of the depressive episodes the alcoholic men experienced were related to the alcohol. The rest of their depression occurred independently from the alcohol.
These findings mean that alcoholism and depression may not always be as linked as some people and researchers have thought.
The study, led by Marc A. Schuckit, MD, of the Department of Psychiatry at the University of California San Diego School of Medicine, assessed both alcoholism and depression in a group of men and their children.
A total of 397 primarily white men were followed for 30 years starting when they were mostly about 20 years old.
At the start of the study, the men were generally healthy, and none were alcoholics or had a history of depression, anxiety, psychotic disorders or substance abuse disorders.
However, half the men were sons of alcoholic fathers, and the other half, who did not have an alcoholic parent, were matched to the first group in terms of age. The researchers also interviewed and followed 449 children of the men.
Over the course of the study, the researchers gathered information on alcohol use disorders, alcohol-induced depressions and independent depressive episodes (that occurred separate from drinking episodes).
During the study's three decades, 15.4 percent of the men experienced at least one severe independent depressive episode, or a period of major depression that was unrelated to using alcohol.
These men did not show any higher risk than the men who did not experience depression in becoming dependent on alcohol or any other illegal substance.
Meanwhile, 164 men (41 percent of the whole group) developed alcoholism over this time, and 31 percent of the depression episodes experienced by the alcoholics were related to drinking.
For the children aged 12 and older, those whose parents had depression were a little more likely to have depression themselves.
However, as with their parents, there was little evidence that the children's depression was caused specifically by alcohol.
The researchers concluded that alcoholism is therefore not necessarily linked specifically to severe depression in that depression necessarily leads to alcoholism. However, both can occur together, and periods of heavy drinking can lead to depression episodes.
"I don't know that the average person realizes that heavy drinking can induce mood problems," Dr. Schuckit said in a statement. "If you're an alcoholic, you're going to have a lot of mood problems. You may be tempted to say, 'Well, I drink a lot because I'm depressed.' You may be right, but it's even more likely that you're depressed because you drink heavily."
The researchers also noted that overall, this study was small and results for women may be different than those for men.
The study was published February 12 in the Journal of Studies on Alcohol and Drugs. The research was funded by the National Institute on Alcohol Abuse and Alcoholism and the National Institutes of Health.