The effect of complete sleep deprivation on the depressive mood and its relationship with changes in self-informed activation

The role of activation on the sleep deprivation anti-depressive effect has been verified in depressive subjects. In a recent study, it was observed th at sleep deprivation provokes deterioration of the depressive mood in healt hy subjects. However, there are also important individual differences as in the case of depressive subjects. Some subjects improve, others experience some deterioration, and still others do not experience any change in their depressive mood with sleep deprivation. The objective of this study is to a nalyze the activation role in the effect of sleep deprivation, on the depre ssive mood of healthy subjects. Specially, the levels of different subjecti ve activation dimensions will be analyzed before and during sleep deprivati on in order to verify if the previous variable levels can predict the sleep deprivation response. In addition, we will analyze if the changes in the a ctivation variables are related to the response to this procedure. The pre- deprivation levels are considered in two forms: the mean level and the main course. A total of 48 healthy subjects (30 women and 18 men) participated in the study. Their ages ranged between 18 and 25 years. The experiment con sisted of a total sleep deprivation of 60 hours (starting on Tuesday at 9:0 0 a.m. and ending on Thursday at 9:00 p.m.). The experiment all groups incl uded from 5 to 7 subjects. Between evaluations, subjects were allowed to re ad, listen to music and watch television. The subjects were under the const ant supervision of two investigators to prevent them from falling sleep. Th e Beck Depression Inventory was administered at 6:00 p.m. on the first day (base line); the second day (after the first night of sleep deprivation), a nd on the third day (after the second night of sleep deprivation) in order to evaluate an), changes in the depressive mood. The self informed activati on levels were evaluated through the Differential Inventory for Mood Study (IDDA-EA), in order to measure three dimensions of the self-informed activa tion: activation, tension, and arousal. The IDDA-EA was administered every 10 hours (at 10:00 a.m., 4:00 p.m., 10:00 p.m., and 4:00 a.m.), 10 times th roughout the length of the experiment. The data show that in healthy subjec ts the total sleep deprivation leads to low activation levels in diverse ty pes of measures. These decreases in the activation level are not related to changes in the depressive mood. Furthermore, the day before sleep deprivat ion the mean levels for these variables are also unrelated to the effect of this procedure. However, a significant relation was found between the diur nal arousal variation during the previous day and the sleep deprivation eff ect on the depressive mood. These data are discussed in relation to the dat a found in depressive subjects.