The odds of depression are significantly elevated for older, obese women and significantly decreased for older overweight men, a study of almost 8,000 adults found.

The results of the study also held in a longitudinal analysis of the same cohort 5 years later.

The findings suggest that more research is needed to determine whether weight loss in older women might lead to a drop in either the prevalence or symptoms of depression, according to Dr. Beate W. Wild of the Medical University Hospital, Heidelberg, Germany, and her colleagues.

The results came from the baseline measurement and second follow-up of the ESTHER study, a cohort study of older adults conducted in Saarland, Germany. Patients were recruited by their primary care physicians during a biannual check-up and completed a self-administered questionnaire that asked about height and weight. One item on the questionnaire asked about past or present occurrence of depression (J. Psychosom. Res. 2012;72:376-82).

In the second follow-up, about 5 years after the initial analysis, patients aged 53-80 years completed another questionnaire that asked again about height and weight. This time, they also were asked to complete the 15-item Geriatric Depression Scale (GDS-15).

Those who were underweight at baseline at the 5-year follow-up were excluded from the sample. In all, 7,808 patients completed the items about height and weight and at least 12 of the GDS-15 items. The participants’ self-reported height and weight were used to calculate their body mass index (BMI), which was categorized into normal weight, overweight, obesity class I, obesity class II, and obesity class III based on criteria from the National Heart, Lung, and Blood Institute.

Using logistic regression analysis, the investigators found that the odds of being depressive were significantly higher for women who were in obesity class II. In an additional analysis that did not control for chronic diseases, the researchers found that the odds of being depressive also were significantly increased for women who were in obesity class III. However, they found a significant, inverse association between depression symptoms in men and overweight.

“That is, overweight men had a lower chance of being depressive than normal weight men,” the investigators wrote.

Dr. Wild and her colleagues found a similar pattern in the longitudinal analysis. Women who were in obesity classes II and III at baseline had significantly higher odds for being depressive 5 years later than did women who were at normal weight at baseline (class II: OR, 1.67; class III: OR, 2.93). Men who were overweight had lower odds of being depressive than did normal weight men (, 0.69).

The researchers speculated that the results in men might be explained by the finding that overweight is the most frequent weight condition in older men.

“Thus, overweight in elderly men appears to be the norm and could, therefore, have been considered (and lived) as the healthier condition by these men.”

Women, however, “tend to be more troubled by obesity than men,” they wrote. This could be tied to the finding in the Midlife in the United States study in which women in obesity class II were three times more likely to report weight discrimination, compared with males in the same obesity class (Int. J. Obesity 2005;29:1011-29).

The investigators reported several limitations. For example, the height and weight of the patients were self-reported. In addition, some studies have suggested that BMI alone might not be an adequate measure for obesity among older adults. Also, scores on the GDS-15 are not comparable to depression diagnoses that are based on structured clinical interviews.

Nevertheless, the findings suggest that more research is needed to determine whether weight loss in older women might lead to a drop in either the prevalence or symptoms of depression, they wrote.

Dr. Wild and her colleagues declared no conflicts of interest.