Passage
Across the lifespan, mental and physical health depends on adequate sleep. Extensive research suggests that sleep needs and characteristics change throughout an individual's life (Figure 1) .
Figure 1 Average hours of rapid eye movement (REM) and non-REM sleep for different age groups across the lifespanChronic sleep deprivation acts as a physiological stressor and can have a multitude of short- and long-term negative health consequences. Studies show that over 30% of adults get less than the recommended minimum of 7 hours of sleep per night, putting them at greater risk for metabolic disorders (eg, obesity, diabetes) , cardiovascular disease (eg, high blood pressure, stroke) , and emotional disorders (eg, anxiety, depression) . Sleep deprivation is also associated with impaired cognitive functioning, decreased work performance, and an increased risk of accidents.However, the guideline that adults sleep at least 7 hours per night does not account for the considerable variation in individual sleep needs. Research suggests that some individuals, known as "long sleepers," require an average daily sleep duration of more than 9 hours, while "short sleepers" require an average daily sleep duration of less than 6 hours. One study found that biological night duration (established by one's circadian pacemaker or "master clock") appears to be a few hours shorter for short sleepers as compared to long sleepers. Other studies suggest that short sleepers regularly sleep less than 7 hours without any apparent negative consequences due to one or more genetic mutations, such as a mutation on the DEC2 gene (also known as BHLHE41) , which codes for a transcription factor involved in regulating circadian rhythms.
-Based on the description in the passage, should an individual who is a "short sleeper" be diagnosed with a sleep-wake disorder?

Question

Passage
Across the lifespan, mental and physical health depends on adequate sleep. Extensive research suggests that sleep needs and characteristics change throughout an individual's life (Figure 1) .

Figure 1 Average hours of rapid eye movement (REM) and non-REM sleep for different age groups across the lifespanChronic sleep deprivation acts as a physiological stressor and can have a multitude of short- and long-term negative health consequences. Studies show that over 30% of adults get less than the recommended minimum of 7 hours of sleep per night, putting them at greater risk for metabolic disorders (eg, obesity, diabetes) , cardiovascular disease (eg, high blood pressure, stroke) , and emotional disorders (eg, anxiety, depression) . Sleep deprivation is also associated with impaired cognitive functioning, decreased work performance, and an increased risk of accidents.However, the guideline that adults sleep at least 7 hours per night does not account for the considerable variation in individual sleep needs. Research suggests that some individuals, known as "long sleepers," require an average daily sleep duration of more than 9 hours, while "short sleepers" require an average daily sleep duration of less than 6 hours. One study found that biological night duration (established by one's circadian pacemaker or "master clock") appears to be a few hours shorter for short sleepers as compared to long sleepers. Other studies suggest that short sleepers regularly sleep less than 7 hours without any apparent negative consequences due to one or more genetic mutations, such as a mutation on the DEC2 gene (also known as BHLHE41) , which codes for a transcription factor involved in regulating circadian rhythms.
-Based on the description in the passage, should an individual who is a "short sleeper" be diagnosed with a sleep-wake disorder?

Quizplus · Accepted Answer

11ecba2d_0c57_ad70_a3bf_dd484d079e45_MD0008_00 Sleep-wake disorders include conditions marked by disturbed sleep causing distress and/or impaired functioning. Sleep-wake disorders fall broadly into two categories: parasomnias and dyssomnias. Parasomnias are more common in children and involve abnormal function of the nervous system during sleep, while falling asleep, or when rousing from sleep. Common examples include somnambulism (sleepwalking) and night terrors (expressing extreme fear or distress while still asleep). Dyssomnias are more common in adults and involve interference with the quality or timing of sleep, such as difficulty falling or remaining asleep, or periods of excessive sleepiness during waking hours. Common examples include insomnia (difficulty sleeping), sleep apnea (impaired breathing during sleep), and narcolepsy (extreme daytime sleepiness). Most dyssomnias involve disruptions to circadian rhythms or the reticular activating system. Individuals with the "short sleeper" phenotype require less than 6 hours of sleep daily on average and appear to be able to regularly sleep less than 7 hours without negative consequences. Because "short sleepers" do not experience distress or impaired functioning, they should not be diagnosed with a sleep-wake disorder. (Choices A and B) While the "short sleeper" phenotype may include sleeping less than average and having shorter-than-average diurnal circadian rhythms, this should not be considered a sleep-wake disorder because individuals with the mutation do not experience distress or impaired functioning. (Choice D) Sleep-wake disorders can arise from causes that are psychological (eg, stress, clinical depression), physical (eg, poorly managed pain), or genetic (eg, gene mutations). Educational objective: Sleep-wake disorders cause disturbed sleep, distress, and impaired functioning. Parasomnias are characterized by abnormal nervous system function during sleep and are more prevalent during childhood. Dyssomnias interfere with the quality or timing of sleep and are more prevalent in adulthood.

Passage Across the Lifespan, Mental and Physical Health Depends on Adequate