Sleep debt

A large sleep debt may lead to mental or physical fatigue, and can adversely affect one's mood, energy, and ability to think clearly.

[citation needed] The effects of chronic sleep debt on the human body's metabolic and endocrine processes are significant, particularly for those individuals who are overweight.

An analysis of the physiological impacts of sleep debt, published in The Lancet, investigated the physiological effects of sleep debt by assessing the sympathovagal balance (an indicator of the sympathetic nervous system activity), thyrotropic function, HPA axis activity, as well as the carbohydrate metabolism of 11 young adult males whose sleep period for six nights was either restricted to four hours per night or extended to 12 hours in bed per night.

[2] Accumulated and continuous short-term sleep deficit has been shown to increase and intensify psychophysiological reactions in humans to emotional stimuli.

[5] As a result, even short-term continuous sleep debt, or deprivation, has been shown to reduce this functional relationship between the amygdala and mPFC, inducing negative mood changes through increased fear and anxiety to unpleasant emotional stimuli and events.

[5] Epidemiological research has solidified the association between sleep debt or deprivation and obesity as a result of an elevated body mass index (BMI) through various ways, such as disruptions in the hormones leptin and ghrelin that regulate appetite, higher food consumption and poor diets, and a decrease in overall calorie burning.

[7][8] However, the harmful consequences of sleep debt over weekdays and weekends were not seen in individuals aged 65 years and older.

The Epworth Sleepiness Scale (ESS), an eight-item questionnaire with scores ranging from 0 to 24, is another tool used to screen for potential sleep debt.

[clarification needed] Inhibition of the Sik3 gene decreases phosphorylation and slow-wave activity in both normal and modified mice.