Sleep disorders (or sleep-wake disorders) involve problems with the quality, timing, and amount of sleep, which result in daytime distress and impairment in functioning. Sleep-wake disorders often occur along with medical conditions or other mental health conditions, such as depression, anxiety, or cognitive disorders. There are several different types of sleep-wake disorders, of which insomnia is the most common. They also include Sleep-Wake Disorders: Insomnia disorder, hyper-somnolence disorder, Narcolepsy. Other sleep-wake disorders include obstructive sleep apnea, parasomnias, narcolepsy, and restless leg syndrome.
Hyper somnolence disorder.
Insomnia disorder involves not getting enough sleep (the prefix in means “lacking” or “without”), and Hyper-somnolence disorders involve sleeping too much (hyper means “in great amount” or “abnormal excess”). Many people who sleep all night find themselves falling asleep several times the next day.
The DSM-5 diagnostic criteria for hyper-somnolence include not only the excessive sleepiness but also the subjective impression of this problem. Several factors that can cause excessive sleepiness would not be considered hyper-somnolence. For example, people with insomnia disorder (who get inadequate amounts of sleep) often report being tired during the day.
In contrast, people with hyper-somnolence sleep through the night and appear rested upon awakening but still complain of being excessively tired throughout the day. Another sleep problem that can cause a similar excessive sleepiness is a breathing-related sleep disorder called sleep apnea.
Diagnostic Criteria for Hyper-somnolence Disorder.
A. Self-reported excessive sleepiness (hyper-somnolence) despite a main sleep period lasting at least 7 hours, with at least one of the following symptoms:
1. Recurrent periods of sleep or lapses into sleep within the same day.
2. A prolonged main sleep episode of more than 9 hours per day that is non-restorative (i.e., unrefreshing).
3. Difficulty being fully awake after abrupt awakening.
B. The hyper-somnolence occurs at least three times per week, for at least 3 months.
C. The hyper-somnolence is accompanied by significant distress or impairment in cognitive, social, occupational, or other important areas of functioning.
D. The hyper-somnolence is not better explained by and does not occur exclusively during the course of another sleep disorder (e.g., narcolepsy, breathing-related sleep disorder, a circadian rhythm sleep–wake disorder, a parasomnia).
E. The hyper-somnolence is not attributable to the physiological effects of a substance (e.g., a drug abuse, a medication).
F. Coexisting mental and medical disorders do not adequately explain the predominance complaint of hyper-somnolence.
Specify if:
Acute: Duration of less than 1 month
Subacute: Duration of 1-3 months
Persistent: Duration of more than 3 months
Specify current severity: Specify severity based on degree of difficulty maintaining daytime alertness as manifested by the occurrence of multiple attacks of irresistible sleepiness within any given day occurring, for example, while sedentary, driving, visiting with friends, or working.
Mild: Difficulty maintaining daytime alertness 1-2 days/week
Moderate: Difficulty maintaining daytime alertness 3-4 days/week
Severe: Difficulty maintaining daytime alertness 5-7 days/week.
Symptoms of Hyper somnolence disorder.
- falling asleep several times during the day
- taking naps to combat the sleepiness but not waking up refreshed
- sleeping more than 9 hours but not feeling rested
- having difficulty waking up from sleep
- feeling confused or combative while trying to wake up
Excessive sleeping may cause problems at work, school, or for other daily activities.
Hyper-somnolence has three categories: acute, subacute, and persistent.
- acute hyper-somnolence, lasting 1 month or less
- subacute hyper-somnolence, lasting 1 to 3 months
- persistent hyper-somnolence, lasting more than 3 months
Hyper-somnolence is similar to another sleep disorder known as narcolepsy in that people experience episodes of sleepiness during the day.
Causes of hyper-somnolence.
- stress
- excessive alcohol consumption
- previous history of viral infection
- previous history of head trauma
- family history of hyper-somnolence
- medical history of depression, substance abuse, bipolar disorder, Alzheimer’s disease, or Parkinson’s disease.
Narcolepsy.
Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep. People with narcolepsy often find it difficult to stay awake for long periods of time, regardless of the circumstances. Narcolepsy can cause serious disruptions in your daily routine. Narcolepsy, a different form of the sleeping problem.
A disorder consisting of excessive daytime sleepiness accompanied by brief “attacks” of sleep during waking hours. These sleep attacks may occur at any time or during any activity, including in potentially dangerous situations such as while driving an automobile. The attacks are often associated with hypnagogic hallucinations, sleep paralysis, and cataplexy and are marked by immediate entry into REM sleep without going through the usual initial stages of sleep. Also called paroxysmal sleep-narcoleptic.
Diagnostic Criteria for Narcolepsy.
A. Recurrent periods of irrepressible need to sleep, lapsing into sleep, or napping occurring within the same day. These must
have been occurring at least three times per week over the past 3 months.
B. The presence of at least one of the following:
1. Episodes of cataplexy defined as either (a) or (b), occurring at least a few times per month:
- (a) In individuals with long standing disease, brief (seconds to minutes) episodes of sudden bilateral loss of muscle tone
with maintained consciousness, precipitated by laughter or joking - (b) In children or in individuals within 6 months of onset, spontaneous grimaces or jaw-opening episodes with tongue thrusting or a global hypotonia, without any obvious emotional triggers.
2. Hypocretin deficiency, as measured using cerebrospinal fluid (CSF) hypocretin-1 immunoreactivity values (less than or equal to one-third of values obtained in healthy subjects tested using the same assay, or less than or equal to 110 pg/ml). Low CSF levels of hypocretin-1 must not be observed in the context of acute brain injury, inflammation or infection.
3. Nocturnal sleep polysomnography showing rapid eye movement (REM) sleep latency less than or equal to 15 minutes, or a multiple sleep latency test showing a mean sleep latency less than or equal to 8 minutes and two or more sleep onset REM periods.
Specify current severity:
Mild: Infrequent cataplexy (less than once per week), need for naps only once or twice per day, and less disturbed nocturnal sleep
Moderate: Cataplexy once daily or every few days, disturbed nocturnal sleep, and need for multiple naps daily
Severe: Drug-resistant cataplexy with multiple attacks daily, nearly constant sleepiness, and disturbed nocturnal sleep (i.e., movements, insomnia, and vivid dreaming)
Causes of Narcolepsy
Many cases of narcolepsy are thought to be caused by a lack of a brain chemical called hypocretin (also known as orexin), which regulates sleep.
The deficiency is thought to be the result of the immune system mistakenly attacking parts of the brain that produce hypocretin. But a lack of hypocretin is not the cause in all cases.
- an inherited genetic fault
- hormonal changes, including those that take place during puberty or the menopause
- major psychological stress
- a sudden change in sleep patterns
- an infection, such as swine flu or a streptococcal infection
- having the flu vaccine Pandemrix
Reference,
David H. Barlow, V. Mark Durand. Abnormal Psychology, An Integrative Approach. (7th ed).