br Discussion Despite the recent publication

Discussion Despite the recent publication of the National Sleep Foundation’s Sleep duration team recommendations [1], sleep deprivation is recognized as important to public health. Industrial accidents, motor vehicle crashes and medical and other occupational errors have been associated with sleep deprivation. [2,3]. Moreover, sleep deprived subjects are also more likely to suffer from chronic diseases such as hypertension, diabetes, depression, and obesity [4], as well as from cancer, increased mortality, and reduced quality of life and productivity [2]. It is indisputable the role and consequences of sleep disorders such as insomnia or obstructive sleep sodium channel blockers for the insufficient amount of sleep in contemporary society. However, sleep deprivation can be also caused by large-scale social and factors such as access to technology and work schedules [2]. Laboratory findings indicated that scheduled napping were able to neutralize the decrease in alertness and performance under conditions of sleep deprivation [5]. Epidemiological studies suggested that the practice of taking short naps several times a week was able to decrease the risk of cardiovascular and cognitive dysfunction [5].
Acknowledgements The authors would like to thank the Núcleo Interdisciplinar da Ciência do Sono – NICS for financial support.
Introduction Insufficient sleep duration affects various brain functions [1] and is associated with behavioral, cognitive, physical, and developmental problems [2–5]. Physical, somatic and mental disturbances are also associated with circadian rhythm disturbances, such as shift work [6], jet lag [6] and social jet lag [7]. Short sleep duration during childhood has been reported to be associated with obesity in adults [8]. However, the long-term effects of unfavorable early daily habits (insufficient sleep duration and disrupted circadian rhythms during the early stages of life) on brain functions are not fully understood [9]. Poor daily habits of modern society (loss of physical contact, decreased physical activity, and short sleep duration with late bed and waking times) during the early stages of life are associated with truancy or dropping out of school, quitting employment, and committing suicide during subsequent years [10]. It has been suggested that deactivation of the serotonergic (5-hydroxytryptamine, 5-HT) system, the dorsal striatum, and the prefrontal cortex (PFC) are the candidate neuronal elements which relate the poor early daily habits with the subsequent unfavorable behaviors [9]. Self-control is known as a significant determinant of success throughout life, although it might be harmful to health by speeding the process of aging, especially for persons who were born into lower social classes [11]. Thus, socioeconomic status (SES) is assumed to affect early development through various elements. Although the famous longitudinal studies by the Mischel group [12–14] and the Dunedin study [15] revealed the association between early self-control and subsequent lives, they did not mention about SES. Anyway, the former [12–14] identified factors to build better lives, such as higher academic scores, better social cognitive and emotional coping, higher educational achievement, higher sense of self-worth, better ability to cope with stress, less risky drug use, and lower body mass. The latter [15] identified good health, good wealth, and low crime outcomes. The current brief paper assesses hypothesis that sufficient sleep duration and proper circadian rhythms during the early stages of life (good early daily habits) are indispensable to having a subsequent adequate social life (successful life) (Fig. 1). However, it should be noted that large inter-individual differences are observed in preferred time of day for completion of distinct cognitive tasks, sleep timing, sleep duration and sleep structure [16], although humans are known to be diurnal animals [17]. Similarly, it is hard to define proper circadian rhythm, however, we now know that pre-industrial people awake just before sunrise and go to sleep 3.3h after sunset [18]. An adequate social life (successful life) was defined according to the famous cohort studies of Mischel\'s and Dunedin [12–15] as a situation with presumable factors to build better lives. As mentioned before, these factors includes social cognitive and emotional coping, higher academic scores, higher educational achievement, higher sense of self-worth, better ability to cope with stress, lower body mass, good health, less risky drug use, low crime outcomes and good wealth..