Major depressive disorder (MDD) with atypical features (including mood reactivity where people can feel better when positive things happen in life, increased appetite or weight gain) appears to be associated with obesity.

MDD has tremendous public health impact worldwide. Obesity is another burden for public health. Understanding the mechanisms underlying the association between MDD and obesity is important.

The study (which had 5.5 years of follow-up) included 3,054 residents (average age nearly 50 years) from Lausanne, Switzerland. The main outcomes were changes in body mass index (BMI), waist circumference and fat mass during follow-up.

At baseline, 7.6 percent of participants met the criteria for MDD. Among the participants with MDD, about 10 percent had atypical and melancholic episodes, 14 percent had atypical episodes, 29 percent had melancholic episodes and 48 percent had unspecified episodes. MDD with atypical features was associated during the follow-up period with a higher increase in adiposity in terms of BMI, incidence of obesity and waist circumference in both sexes, as well as fat mass in men. The study suggests the higher BMI increase in participants with MDD with atypical features also was not temporary and persisted after remission of the depressive episode.

"For the clinician, the atypical subtype deserves particular attention because this subtype is a strong predictor of adiposity. Accordingly, the screening of atypical features and, in particular, increased appetite in individuals with depression is crucial. The prescription of appetite-stimulating medication should be avoided in these patients and dietary measures during depressive episodes with atypical features are advocated. "

The study was published in JAMA Psychiatry.