به چالش کشیدن اعتبار همبستگی میان پر خوابی و پرخوری در افسردگی آتیپیک

Objective In this study, we used a strict definition of hypersomnia and tested if the association between overeating–hypersomnia remained positive and significant. Hypersomnia was present if the total sleep time was close to 10 h per day or was at least 2 h longer than in normothymic periods. Methods Cross-sectional study using the adult general population of California and New York. The sample was composed of 6694 individuals aged between 18 and 96 years. Participants were interviewed by telephone using the Sleep-EVAL system. The interviews included various sleep and health topics and the assessment of DSM-IV sleep and psychiatric disorders. Results The one-month prevalence of major depressive episode was 6.1%, including a one-month prevalence of atypical depression of 1.6%, in this sample. Atypical depression subjects had a greater number of depressive symptoms and a longer duration of the current depressive episode than the other depressive subjects. Depressive subjects with hypersomnia slept longer (8 h, 29 min) than the other depressive subjects (6 h, 36 min) and longer than the subjects “getting too much sleep” (6 h, 48 min). Furthermore, hypersomnia was not associated with overeating while “getting too much sleep” showed a positive association with overeating. Conclusions Hypersomnia needs to be evaluated using a strict definition. Otherwise, it leads to an overestimation of this symptom in major depressive episode subjects and to a false association with overeating.

Atypical depression was first introduced in the fourth edition of the DSM [1]. The essential criterion of atypical depression is mood reactivity. To meet full criteria, mood reactivity must also be accompanied by at least two of the following symptoms: leaden paralysis, hypersomnia, weight gain/increased appetite or sensitivity to rejection. Historical origins of atypical depression developed from empirical findings of antidepressants trials [2], [3], [4] and [5]. The diagnosis of atypical depression as per the DSM-IV remains controversial. Some studies supported the validity of the criteria set [6] and [7], others have only reported a partial validity of the concept [8], [9] and [10] while still others found no support for the concept [11]. In community surveys, the assessment of atypical depression is mainly based on the assessment of the reversed neurovegetative symptoms (overeating and oversleeping) in individuals with major depressive episodes (MDE) [12] and [13] instead of using the combination of mood reactivity with the four other symptoms described in the DSM-IV. For example, the Sullivan et al. [6] study limited the analyses to hypersomnia (oversleeping) and overeating or weight gain. In another study [7], leaden paralysis was defined as fatigue or weakness. The Columbia group varied the inclusion criteria using one or two atypical features in combination with mood reactivity [2], [14] and [15]. In the general population and in sleep disorder centers, the association between overeating and oversleeping is rarely seen. On the contrary, obesity and weight gain have been associated with shorter sleep [13], [16], [17] and [18]. A possible explanation of the high association between overeating and oversleeping in subjects with major depressive episodes can be the broad definition of oversleeping. While overeating is often strictly defined as a significant weight gain (~ 5 lb or more) or an increase in the appetite nearly every day for a period of 2 weeks or longer, oversleeping is defined broadly as a subjective sense of sleeping “too much” nearly every day for a period of 2 weeks or longer. The aims of this study are: 1) to evaluate the association of “overeating and oversleeping” in people experiencing a major depressive episode, using a more precise definition of hypersomnia rather than a vague and subjective sense of “oversleeping”. Hypersomnia is a total sleep duration per 24-hour period of 10 h or more (or a normal sleep duration accompanied of daytime sleep episode(s) lasting 1 h or more) for a period of two weeks [19]. This definition of hypersomnia is similar to one proposed in the DSM-IV for depressive disorders. 2) to estimate the frequency of atypical symptoms in DSM-IV major depressive episode and 3) to verify the relevance of the concept of atypical depression in the general population.

Participants in this study were aged between 18 and 96 years. Half were married. Nearly 60% were working; the unemployment rate was 4.8%. The average body mass index (BMI) for the sample was 27.8 (± 5.6) kg/m2. The rate of obesity (BMI ≥ 30 kg/m2) was 28.7% and the rate of morbid obesity (BMI ≥ 40 kg/m2) was 3.9%. The two states had some differences in age (Californians were younger), education (more individuals in California had at least some college education), race (more Hispanic and Asian in California) and BMI (individuals in New York were heavier).