The number of people who drink alcohol is growing. Depression is the most prevalent mental disorder in the world, with an increasing number of diagnoses. But are the two intrinsically linked? According to a new study, people who drink wine in moderation may actually suffer from lower rates of depression.
The study, conducted by a team of Spain's top preventive medical practitioners and clinicians, notes that, "the simultaneous presence of alcohol-related problems and depression is common." But, the team writes in the journal BMC Medicine, prior research shows wine drinkers tend to be healthier. The scientists wanted to test if such health benefits might affect mental well-being. For example, cardiovascular disease and depression share some physiological traits, and wine is a well-established heart helper.
To test their ideas, the team pulled health data from 5,505 men and women participating in the larger PREDIMED study, which examines the impact of the Mediterranean diet on heart disease. None of the participants reported depression, alcohol problems or other notable ailments when they joined the study.
After a seven-year followup, the researchers noted how many subjects were clinically diagnosed with depression and analyzed alcohol-consumption habits. They found that moderate intake of alcohol—within the range of 5 to 15 grams per day (roughly one serving, or the amount found within a typical 5-ounce glass of wine)—is associated with a 28 percent lower chance of depression. And wine consumption in the range of two to seven glasses per week was associated with a 32 percent lower rate of depression.
"Wine alone may help to prevent depression among people who are not depressed," co-author Miguel Martínez-González told Wine Spectator. "However, we cannot say that wine may help those who are already depressed." Martínez-González, who practices preventive medicine at the University of Navarra in Pamplona, added that the results are applicable to populations outside Spain.
Not everyone agrees with the conclusions. In a review of the findings, Dr. Harvey Finkel, a hematologist at the Boston University Medical Center, said he cannot support a physiological parallel between cardiovascular disease and depression in relation to alcohol. "Drinking is often a symptom of depression, likely an attempt at self-medication, and drawing a deeper significance from the conflation of the two seems to me untenable," he said.
The Spanish scientists have a few theories for their results. It's possible that people who drink wine enjoy better mental health for unrelated lifestyle reasons. Also, the red wine compound resveratrol is theorized to hold neuroprotective properties. "Neuroprotection applied to the hippocampus may prevent moderate wine drinkers from developing depression," the study reads. Previous investigations suggest the hippocampus may play a role in the development of severe depression.
However, the study notes that the incidence of depression could be inaccurately assessed. "If heavy drinkers were less likely to seek medical care, this could result in the rates of depression being underestimated among heavy drinkers," they concluded.