Can only reversed vegetative symptoms define atypical depression?

BACKGROUND

The definition of atypical depression (AD) has recently seen a rebirth of studies, as the evidence supporting the current DSM-IV atypical features criteria is weak. Study aim was to compare a definition of AD requiring only oversleeping and overeating (reversed vegetative symptoms) to the DSM-IV AD definition (always requiring mood reactivity, plus overeating/weight gain, oversleeping, leaden paralysis, and interpersonal sensitivity [at least 2]).

METHODS

Consecutive 202 major depressive disorder (MDD) and 281 bipolar II outpatients were interviewed, during a major depressive episode (MDE), with the Structured Clinical Interview for DSM-IV. The DSM-IV criteria for AD were compared to a new AD definition based only on oversleeping and overeating, which was the one often used in community studies. Associations were tested by univariate logistic regression.

RESULTS

The frequency of DSM-IV AD was 42.8 %, and that of the new AD definition was 38.7 %. DSM-IV AD, and the new AD definition, had almost all the same significant associations: bipolar II, female gender, lower age, lower age of onset, axis I comorbidity, depressive mixed state, MDE symptoms lasting more than 2 years, and bipolar family history. DSM-IV AD was present in 86 % of the new AD definition sample. The new definition of AD was significantly associated with all the other DSM-IV AD symptoms not included in it. The new AD definition was strongly associated with DSM-IV AD (odds ratio = 17.8), and had sensitivity = 77.7 %, specificity = 90.5 %, positive predictive value = 86.1 %, negative predictive value = 84.4 %, and ROC area curve = 0.85, for predicting DSM-IV AD.

CONCLUSIONS

Results support a simpler definition of AD, requiring only oversleeping and overeating, and support the similar AD definition previously used in community studies. This definition is easier and quicker to assess by clinicians than the DSM-IV definition (mood reactivity and interpersonal sensitivity are more difficult to assess). Some pharmacological studies support this new AD definition (by showing better response to MAOI than to TCA, as shown in DSM-IV AD).