It's like the old question, which came first, the chicken or the egg? But this time researchers are talking about alcohol abuse and depression. Does the former cause the latter, or is it visa versa?
Many have believed depression leads to alcohol problems, because people who are depressed turn to alcohol to make them feel better, at least for a time. New Zealand investigators suggest the opposite is true: alcohol abuse actually leads to depression.
They arrived at that conclusion after looking at health data on about 1,000 people born in 1977. Rates of alcohol abuse and depression ran between about 18 percent and about 14 percent each as the participants moved from their late teens into their early 20s. Using three statistical models, the researchers tried to determine which came first: alcohol abuse or depression. One model assumed the two conditions were responsible for each other. Another assumed alcohol problems caused depression. And the third assumed depression caused alcohol problems.
"The analysis suggested that the best-fitting model was one in which there was a unidirectional association from alcohol abuse or dependence to major depression but no reverse effect from major depression to alcohol abuse or dependence," write the authors.
How would alcohol abuse lead to depression? The researchers aren't sure, but speculate alcohol might trigger genetic markers that increase the risk for depression, or alcohol's depressive characteristics may lead to periods of depression in those who overindulge.