Variations in the sleep–wake cycle from childhood to adulthood: chronobiological perspectives

Abstract:

Changes in the sleep–wake cycle across development from childhood to adulthood, typically involve a steady shortening of the sleep period and a delay of sleep phase, with a period of more rapid change across adolescence. Accompanying these changes is the maturation of neuroendocrine rhythms such as melatonin, cortisol, and pubertal hormones. These endogenous rhythms are closely associated with behavioral changes in rest and activity rhythms, although environmental factors such as light exposure and academic and social demands likely play an interactive role. Other behavioral aspects, such as physical activity and eating behaviors, are also associated with changes in sleep–wake rhythms, and may be mediational factors in the development of physical illnesses. The sleep–wake cycle and related factors are implicated in the development of mental illnesses. There are several potential avenues of future research that may be valuable in terms of improving interventions and treatments for both mental and physical illnesses.

Keywords::

• circadian rhythm
• developmental
• adolescence
• youth

Disclosure

The authors would like to declare the following conflicts of interest: IBH is a Commissioner in Australia’s new National Mental Health Commission from 2012. He was a director of headspace: the national youth mental health foundation until January 2012. He was previously the chief executive officer (till 2003) and clinical adviser (till 2006) of beyond blue, an Australian National Depression Initiative. He is the executive director of the Brain and Mind Research Institute, which operates two early-intervention youth services under contract to headspace. He has led a range of community-based and pharmaceutical industry-supported depression awareness and education and training programs. He has led projects for health professionals and the community supported by governmental, community agency and pharmaceutical industry partners (Wyeth, Eli Lily, Servier, Pfizer, and AstraZeneca) for the identification and management of depression and anxiety. He has received honoraria for presentations of his own work at educational seminars supported by a number of non-government organizations and the pharmaceutical industry (including Servier, Pfizer, AstraZeneca, and Eli Lilly). He is a member of the Medical Advisory Panel for Medibank Private and also a Board Member of Psychosis Australia Trust. He leads an investigator-initiated study of the effects of agomelatine on circadian parameters (supported in part by Servier) and has participated in a multicenter clinical trial of the effects of agomelatine on sleep architecture in depression and a Servier-supported study of major depression and sleep disturbance in primary care settings.

The authors also note the following financial disclosures: IBH was funded by a National Health and Medical Research Council Program Grant (No 566529) and Australian Fellowship (No 464914). RR received a postdoctoral training award from the Fonds de la recherche en sante du Quebec. JSC was supported by the NHMRC Centre of Research Excellence in Optimising Early Interventions for Young People with Emerging Mood Disorders (No 1061043). The funders had no role in the decision to publish, or preparation of this manuscript.