When most people think of major depression, they probably don't realize there are different types. But there are, and certain types can affect other health concerns.
A recent study found that those with atypical major depressive disorder were more likely to gain more weight than those with no depression.
However, those with other types of major depression, such as melancholic or "unspecified," did not experience more weight gain than those who weren't depressed.
It's not clear why those with atypical depression had a higher risk.
This study, led by Aurelie Lasserre, MD, of Lausanne University Hospital in Switzerland, looked at whether weight gain was associated with different subtypes of depression.
There are four different subtypes of major depressive disorder. These include atypical, melancholic, a combination of atypical and melancholic, or unspecified.
The authors followed 3,054 individuals for an average of 5.5 years, starting in 2003.
All of these individuals lived in Lausanne, Switzerland, and 7.6 percent of them had some kind of major depressive disorder at the start of the study.
Further, more than a third of them (37 percent) had previously experienced an episode of major depression.
Over the course of the study, regular measurements of the individuals' body mass index (BMI), fat mass and waist circumference were compared to those with and without depression.
BMI is a ratio of a person's height to weight, which is used to determine whether they are a normal, healthy weight.
The researchers found that those with atypical depression had 3.75 times greater odds of being obese over the course of the study than those without depression. This was true after taking into account differences among the participants' demographics and alcohol or tobacco use, medication use or physical exercise.
These researchers also found a link between atypical major depression and waist circumference and BMI for men and women. The same link showed up for fat mass in men.
Those findings mean that those with atypical depression were more likely than those without any depression to have a higher BMI and/or waist circumference.
The authors did not find that physical exercise or taking medication made a difference to the increased risk of obesity among those with atypical depression.
This study was published June 4 in the journal JAMA Psychiatry.
The research was funded by the Swiss National Science Foundation and GlaxoSmithKline. No potential conflicts of interest were reported.