The role of activation in the effect of total sleep deprivation on depressed mood

The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one

STUDY OBJECTIVES

New theory and measurement approaches have facilitated nuanced investigation of how sleep loss impacts dimensions of affective functioning. To provide a quantitative summary of this literature, three conceptually related meta-analyses examined the effect of sleep restriction and sleep deprivation on mood, emotion, and emotion regulation across the lifespan (i.e. from early childhood to late adulthood).

METHODS

A total of 241 effect sizes from 64 studies were selected for inclusion, and multilevel meta-analytic techniques were used when applicable.

RESULTS

There was a moderate, positive effect of sleep loss on negative mood (g = 0.45), which was stronger for studies with younger samples, as well as a large, negative effect of sleep loss on positive mood (g = -0.94). For negative mood only, studies that used total sleep deprivation had larger effect sizes than studies that restricted sleep. After correcting for publication bias, a modest but significant negative effect for sleep loss on emotion (g = -0.11) was found; the valence of emotional stimuli did not change the direction of this effect, and type of sleep manipulation was also not a significant moderator. Finally, sleep restriction had a small, negative effect on adaptive emotion regulation (g = -0.32), but no significant impact on maladaptive emotion regulation (g = 0.14); all studies on adaptive emotion regulation were conducted with youth samples.

CONCLUSIONS

Sleep loss compromises optimal affective functioning, though the magnitude of effects varies across components. Findings underscore the importance of sleep for healthy affective outcomes.

Does caffeine change the effect of sleep deprivation on moderate to severe depressed patients?

INTRODUCTION

Sleep deprivation (SD) has been used as an alternative approach to treat major depressive disorder (MDD). Caffeine, due to its stimulating effect, could be an alternative to promote sleep deprivation. However, there are no data about its potential influence on the antidepressive effect of SD. The objective of this study is to assess the effect of caffeine on SD in non-psychotic patients with moderate to severe unipolar depression.

METHODS

Randomized, double-blind, crossover clinical trial comparing caffeine and placebo in moderate to severe depressed patients who underwent total sleep deprivation (SD). The patients were assessed with items of the Bond-Lader scale, the 6-item Hamilton Depression Rating Scale (HAMD-6), and the Clinical Global Impression (CGI)-Severity/Improvement.

RESULTS

Twenty patients participated in this study. The patients who consumed caffeine presented the same level of energy before and after sleep deprivation (lethargic-energetic item of the Bond-Lader scale), while the patients in the placebo group had a reduced level of energy after sleep deprivation (p=0.0045). There was no difference between the caffeine and placebo groups in the other items of the Bond-Lader scale.

CONCLUSION

The combined use of caffeine and SD can be a useful strategy to keep the patient awake without impairing the effect of SD on depressed outpatients. However, further studies involving patients who have responded to SD are needed in order to verify if caffeine also does not interfere with the results in this group.