Changes in Sleep patterns over life

Delayed sleep onset

-As adolescents normally have a set waking time, delayed sleep onset results in sleep dept. -Adolescents usually make this time up on the weekend, but can lead to symptoms of partial sleep deprivation (discussed in upcoming PPT). -As adolescents normally have a set waking time, delayed sleep onset results in sleep dept. -Adolescents usually make this time up on the weekend. -Shift workers may also suffer delayed sleep onset. -One medical treatment is taking melatonin.

Psychological and Social factors which impact on adolescent sleep patters.

-Adolescents typically like to exert their growing need for independence, which can include making decisions about when to go to bed or sleep. -Many usually decide to go to sleep later, particularly as early sleep times are associated with childhood. -Adolescents also experience increased demands on their time for socialising and increased academic or work demands compared to when they were children which can push back their sleep time.

Biological factors which impact on adolescent sleep patters.

-Every day our body goes through a sleep/wake cycle that revolves around night and day. This regular cycle is called a circadian rhythm which includes a shift in the hormonal levels in our body throughout the day. -The sleep hormone melatonin causes us to feel sleepy at night. -The cycle is linked to external cues in the environment, such as the presence or absence of sunlight, alarm clocks, meal times and even television -During adolescence, there is a hormonally induced shift of the body clock forward by about 1 to 2 hours, making the adolescent sleepier 1 to 2 hours later. This is known as the sleep-wake cycle shift. -sleep-wake cycle shift affects an adolescent's ability to fall asleep at the earlier times expected of them as a child. -However, early school (or work) starts don't allow an adolescent to sleep in and get the additional sleep that would naturally occur. -This nightly sleep loss can accumulate as a sleep debt; that is, sleep that is owed and needs to be made up.

Changes in REM and NREM sleep

-Key points (on average): -Infants sleep 16h with 50% REM -Adolescents sleep 8-9h with 20% REM -The elderly sleep 6h with 20% REM -Overall, the amount of sleep time and REM sleep decreases over the lifetime. -Some research suggests that females require more sleep than males.

Sleep-wake cycle shift

-Sleep-wake cycle shift - a hormonal induced shift of the body clock by about one to two hours. -For adolescents this is termed delayed sleep onset. -This occurs because the hormone melatonin is released later in the day.

Sleep-wake cycles during adolescence

-Studies of adolescent sleep patterns indicate that this population tends to have sleep problems, such as requiring a long time to fall asleep, insufficient night-time sleep on weekdays and difficulty waking up in the mornings. -Psychologists explain these sleep problems in terms of -Biological -Psychological; and -Social factors.

SLEEP PATTERNS ACROSS THE LIFESPAN

-The duration of time required to have a good night's rest varies from person to person and is based on a number of factors including age, lifestyle and genetics. -The amount of time spent in NREM and REM sleep also changes according to different stages of our lives. Age -The amount of sleep varies with age. -Most teenagers need 9-10 hours per night. - A young child needs more and an adult less to perform at their best. Lifestyle -For instance, working day or night shifts, sleeping in quiet or noisy places, leading an active versus inactive lifestyle all influence our individual need for sleep. -Culture - some cultures take afternoon naps. Genetics -Some studies suggest that females tend to need more sleep than males (Wever1984). -The amount of time we spend sleeping decreases as we get older. -The proportion of total sleep time spent in REM sleep decreases markedly from infancy to adolescence, and then remains relatively stable into adulthood and old age. -The amount of NREM sleep time also decreases, but compared with the drop in REM sleep up to adolescence, NREM sleep tends to be relatively stable. There is a gradual decrease in total time spent sleeping as we age There is a gradual decrease in REM sleep from birth to adolescence followed by a slight increase in late adulthood. There is a gradual increase in NREM sleep from birth to adolescence and then a drop in late adulthood.