Atypical features in depression: Association with obesity and bipolar disorder.

Objectives: Depression with atypical features amounts to a significant proportion of depressed patients. Studies have shown its association with bipolarity and, recently, with obesity. In this study, we investigated atypical features of depression in relation to overweight/obesity in three diagnostic categories: unipolar depression, bipolar depression and dysthymia.

Methods: Out of 512 depressed patients screened, we recruited 182 research subjects, consisting of 91 pairs, matched by age, gender and diagnosis, in which one member of the pair was within the normal weight range (BMI≤25) and the other was either overweight or obese (BMI>25). There were 35 pairs with unipolar depression, 27 with bipolar depression and 29 with dysthymia. Symptoms of atypical depression, such as increased appetite, hypersomnia, leaden paralysis, longstanding pattern of interpersonal rejection sensitivity, and, a significant weight gain in the past 3 months, were assessed.

Results: All the symptoms of atypical depression were significantly more pronounced in those depressed patients with a BMI>25, compared with depressed subjects with a normal weight. Except for hypersomnia, these symptoms scored significantly higher in women compared to men. Among the diagnostic categories, symptoms of atypical depression were significantly higher in patients with bipolar disorder compared with both major depressive disorder and dysthymia.

Limitations: The preponderance of women, the assessment of atypical depression by adaptation of the DSM criteria, entirely Polish population, specificity of selection criteria.

Conclusions: The results demonstrated a higher intensity of atypical depression's symptoms in overweight/obese depressed patients. They also confirm the association between obesity and bipolarity.