The decrease in the quantity and quality of the NREM SWS as well as the disturbances of sleep will therefore increase the AB plaques.[29][30] This will first take place at the hippocampus level, from which memory is dependent.[29][30] This will result in cell death at this level and will contribute to diminished memory performances and cognitive decline found in AD disease.[29]
Restless leg syndrome (RLS) is an overwhelming need to move the legs. This urge is sometimes accompanied by a tingling sensation in the legs. While these symptoms can occur during the day, they are most prevalent at night. RLS is often associated with certain health conditions, including ADHD and Parkinson’s disease, but the exact cause isn’t always known.
A systematic review states 7.6% of the general population experiences sleep paralysis at least once in their lifetime. Its prevalence among men is 15.9% while 18.9% of women experience it. When considering specific populations, 28.3% of students and 31.9% of psychiatric patients have experienced this phenomenon at least once in their lifetime. Of those psychiatric patients, 34.6% have panic disorder. Sleep paralysis in students is slightly more prevalent for those of Asian descent (39.9%) than other ethnicities (Hispanic: 34.5%, African descent: 31.4%, Caucasian 30.8%).[67]

Neurodegenerative diseases have been often associated with sleep disorders, mainly when they are characterized by abnormal accumulation of alpha-synuclein, such as multiple system atrophy (MSA), Parkinson's disease (PD) and Lewy body disease (LBD).[21][22][23][24][25][26][27] For instance, people diagnosed with PD have often presented different kinds of sleep concerns, commonly regard to insomnia (around 70% of the PD population), hypersomnia (more than 50% of the PD population), and REM sleep behavior disorder (RBD) - that may affect around 40% of the PD population and it is associated with increased motor symptoms.[21][22][23][24][25][27] Importantly, RBD has been also highlighted as a strong precursor of developing dementia in PD patients over several years in prior, which seems to be a great opportunity for improving the treatments of the disease.[22][24]

Women often experience sleepless nights and daytime fatigue in the first and third trimesters of their pregnancy. During the first trimester, frequent trips to the bathroom and morning sickness may disrupt sleep. Later in pregnancy, vivid dreams and physical discomfort may prevent deep sleep. After delivery, the new baby's care or the mother's postpartum depression may interrupt sleep.
Sleep disorders are a group of conditions that affect the ability to sleep well on a regular basis. Whether they are caused by a health problem or by too much stress, sleep disorders are becoming increasingly common in the United States. In fact, more than 75 percent of Americans between ages 20 and 59 report having sleeping difficulties fairly regularly.
With over 80 listed sleep disorders, and more that are being researched, it's important for patients suffering from the various types of sleep disorders to seek medical treatment. If you believe that your sleep problems may be caused by a disorder, there are many things you can do to solve your sleep issues from DIY tips and tricks such as practicing better sleep hygiene, to contacting a sleep clinic to schedule an inlab sleep study, or an at home sleep test for certain pre-screened disorders such as obstructive sleep apnea.
In addressing sleep disorders and possible solutions, there is often a lot of buzz surrounding melatonin. Research suggests that melatonin is useful in helping people to fall asleep faster (decreased sleep latency), to stay asleep longer, and to experience improved sleep quality. In order to test this, a study was conducted that compared subjects that had taken Melatonin to subjects that had taken a placebo pill in subjects with primary sleep disorders. Researchers assessed sleep onset latency, total minutes slept, and overall sleep quality in the Melatonin and placebo groups to note the differences. In the end, researchers found that melatonin decreased sleep onset latency, increased total sleep time, and improved quality of sleep significantly more than the placebo group.[49][50]

Narcolepsy is a sleep disorder that involves excessive, uncontrollable daytime sleepiness. It is caused by a dysfunction of the brain mechanism that controls sleeping and waking. If you have narcolepsy, you may have “sleep attacks” in the middle of talking, working, or even driving. Although no cure yet exists, a combination of treatments can help control symptoms and enable you to enjoy many normal activities.


In Alzheimer's disease, in addition to cognitive decline and memory impairment, there is also significant sleep disturbances with a modified sleep architecture.[30][29] The latter may consist in sleep fragmentation, a reduction in sleep duration, insomnia, an increase daytime naping, a decreased quantity og some sleep stages and a resemblance between some sleep stages (N1 and N2).[29] More than 65% of people with Alzheimer's disease suffer from this type of sleep disturbance.[29]
The decrease in the quantity and quality of the NREM SWS as well as the disturbances of sleep will therefore increase the AB plaques.[29][30] This will first take place at the hippocampus level, from which memory is dependent.[29][30] This will result in cell death at this level and will contribute to diminished memory performances and cognitive decline found in AD disease.[29]
One factors that could explain this change in sleep architecture is a change in circadian rhythm, which regulates sleep.[29] A disruption of the circadian rhythm would therefore generate sleep disturbances.[29] Some studies show that people with AD have a delayed circadian rhythm, whereas in normal aging we will find an advanced circadian rhythm.[29][31]
Delayed sleep phase disorder is a condition where your biological clock is significantly delayed. As a result, you go to sleep and wake up much later than other people. This is more than just a preference for staying up late or being a night owl, but rather a disorder that makes it difficult for you to keep normal hours—to make it to morning classes, get the kids to school on time, or keep a 9-to-5 job.
^ Hirshkowitz, Max (2004). "Chapter 10, Neuropsychiatric Aspects of Sleep and Sleep Disorders (pp 315-340)" (Google Books preview includes entire chapter 10). In Stuart C. Yudofsky; Robert E. Hales (eds.). Essentials of neuropsychiatry and clinical neurosciences (4 ed.). Arlington, Virginia, USA: American Psychiatric Publishing. ISBN 978-1-58562-005-0. ...insomnia is a symptom. It is neither a disease nor a specific condition. (from p. 322)
On the other hand, it is during sleep that beta-amyloid residues are degraded to prevent plaque formation.[29][30][32] It is the glymphatic system that is responsible for this and this phenomenon is called glymphatic clearance.[29][30][32] Thus, during wakefulness, the AB burden is greater because the metabolic activity and oxidative stress are higher and there is no degradation of the protein by the glymphatic clearance whereas during sleep, the burden will be smaller as there will be less metabolic activity and oxidative stress in addition to the glymphatic clearance that occurs at this time.[30][29]
Get back to sleep when you wake up at night. Whether you have a sleep disorder or not, it’s normal to wake briefly during the night. If you’re having trouble getting back to sleep, try focusing on your breathing, meditating, or practicing another relaxation technique. Make a note of anything that’s worrying you and resolve to postpone worrying about it until the next day when it will be easier to resolve.
Sleep disturbances have been also observed in Alzheimer's disease (AD), affecting about 45% of its population.[22][24][26] Moreover, when it is based on caregiver reports this percentage is even higher, about 70%.[28] As well as in PD population, insomnia and hypersomnia are frequently recognized in AD patients, which have been associated with accumulation of Beta-amyloid, circadian rhythm sleep disorders (CRSD) and melatonin alteration.[22][24][28] Additionally, changes in sleep architecture are observed in AD too.[22][24][26] Even though with ageing the sleep architecture seems to change naturally, in AD patients it is aggravated. SWS is potentially decreased (sometimes totally absent), spindles and the time spent in REM sleep are also reduced, while its latency is increased.[28] The poorly sleep onset in AD has been also associated with dream-related hallucination, increased restlessness, wandering and agitation, that seem to be related with sundowning - a typical chronological phenomenon presented in the disease.[24][28]
Chronic sleep disorders in childhood, which affect some 70% of children with developmental or psychological disorders, are under-reported and under-treated. Sleep-phase disruption is also common among adolescents, whose school schedules are often incompatible with their natural circadian rhythm. Effective treatment begins with careful diagnosis using sleep diaries and perhaps sleep studies. Modifications in sleep hygiene may resolve the problem, but medical treatment is often warranted.[35]
A systematic review states 7.6% of the general population experiences sleep paralysis at least once in their lifetime. Its prevalence among men is 15.9% while 18.9% of women experience it. When considering specific populations, 28.3% of students and 31.9% of psychiatric patients have experienced this phenomenon at least once in their lifetime. Of those psychiatric patients, 34.6% have panic disorder. Sleep paralysis in students is slightly more prevalent for those of Asian descent (39.9%) than other ethnicities (Hispanic: 34.5%, African descent: 31.4%, Caucasian 30.8%).[67]
There are many possible causes of restless legs syndrome, including kidney failure, nerve disorders, vitamin and iron deficiencies, pregnancy, and some medications (such as antidepressants). Recent studies have shown a strong genetic link and researchers have been able to isolate a gene that may be responsible for at least 40% of all cases of the disorder.

Narcolepsy is a sleep disorder that involves excessive, uncontrollable daytime sleepiness. It is caused by a dysfunction of the brain mechanism that controls sleeping and waking. If you have narcolepsy, you may have “sleep attacks” in the middle of talking, working, or even driving. Although no cure yet exists, a combination of treatments can help control symptoms and enable you to enjoy many normal activities.
Keep a pen and paper next to your bed. If you're often kept awake by racing thoughts and worries and you tend to make to-do lists in your head, keep a pen or pencil and a small pad of paper handy and write them down. As you put each item down on paper, imagine yourself setting aside that concern. (Again, use a book light; don't turn on the overhead or a bright bedside light to write.)
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