A new study from New Zealand suggests that alcohol may trigger depression, and disputes previous findings that suggest the reverse is true, MedPage Today reported Mar. 2.
Researchers from the University of Otago's Christchurch School of Medicine and Health Sciences arrived at their conclusion using statistical models applied to a group of individuals with alcohol problems and major depression. They cautioned that the results should be viewed as “suggestive rather than definitive.”
The researchers reviewed data gathered from the Christchurch Health and Development study, which followed 1,055 New Zealanders from birth to age 25 years. Subjects were interviewed at the ages of 18, 21, and 25.
At age 18, 19.4 percent had alcohol problems and 18.2 percent had major depression; at age 21, 22.4 percent had alcohol problems and 18.2 had major depression, and at the final interview, 13.6 percent had alcohol problems and 13.8 percent had major depression.
On average, alcohol was associated with nearly double the risk of major depression among the study participants.
Using three models based on the data — one in which alcohol problems and depression exacerbated one another, one in which major depression caused alcohol problems, and one in which alcohol problems caused major depression — the researchers determined that the model that assumed that alcohol problems caused major depression was the best fit.
“The underlying mechanisms that give rise to such an association are unclear,” the researchers said, adding that “further research suggests that alcohol's depressant characteristics may lead to periods of depressed affect among those with alcohol abuse or dependence.”
The study appeared in the March 2009 issue of Archives of General Psychiatry.