We’ve all had occasional nights in which we’ve stayed up too late because we couldn’t fall asleep. These nights we may have been afflicted with insomnia, a condition characterized primarily by an inability to fall asleep. What many people don’t know is that insomnia isn’t always considered an inability to fall asleep, rather it sometimes appears as an inability to stay asleep or manifests as consistently waking up too early.
Those that have trouble transitioning from a state of wakefulness to sleep have the most common type of insomnia known as “sleep-onset insomnia.” Those with an inability to stay asleep are said to have “sleep-maintenance insomnia.” Although “sleep-onset” and “sleep-maintenance” insomnia are two of the most commonly reported subtypes, there are numerous others that have been documented by the American Academy of Sleep Medicine (AASM).
3 General Types of Insomnia
Insomnia is generally classified as being one of 3 primary types including: acute (moderate-term), chronic (long-term), or transient (short-term).
1. Acute Insomnia (<1 Month)
Those with acute insomnia have experienced sleeping difficulties such as inability to fall asleep or inability to stay asleep for less than one month. Should the sleep difficulties persist for longer than a month, an individual would be diagnosed with “chronic” insomnia. The insomnia diagnosis can be made when an individual isn’t able to get proper sleep, yet has sufficient opportunity and suitable environmental circumstances to get sleep.
In many cases, a person may discover that acute insomnia can impair cognitive function and physical performance. Despite the fact that acute insomnia doesn’t persist for longer than approximately 30 days, it may interfere with a person’s social life, work-performance, or health. Due to the fact that stress is usually the cause of acute insomnia, it is sometimes referred to as “stress-related insomnia.”
2. Chronic Insomnia (1+ Month)
Individuals with chronic insomnia are considered to have the condition for longer than the month. In some cases, a person may deal with chronic insomnia for years or even a bulk of their life if they don’t seek proper treatment. Sometimes chronic insomnia can be caused by another medical condition such as a neurological disorder or mental illness.
Research has shown that individuals with chronic insomnia tend to have significantly different levels of hormones. Specifically chronic sufferers tend to have abnormally low melatonin levels and high coritsol, which interferes with various stages of sleep (e.g. rapid-eye movement). There is increasing evidence that chronic insomnia may speed up aging in part due to less slow-wave sleep, resulting in decreased physiological restoration.
In the most severe cases of chronic insomnia, a person may feel muscularly fatigued, be unable to be a productive member of society, and may even experience hallucinations as a result of sleep deprivation. For health-related reasons, it is important to treat this condition as soon as it is recognized.
3. Transient Insomnia (1 Week)
A third primary type of insomnia is considered “transient” or temporary. Transient insomnia is often untreated because it generally subsides within one week. Should it last longer than a week, it would fit the diagnosis of an “acute” insomnia. The cause of transient insomnia may be related to environmental changes, jet lag, stress, or medical conditions.
In some cases, transient insomnia may only last a couple days, while for others it may last nearly a fully week. Most individuals with transient insomnia notice a decline in performance as a result of their inability to fall asleep and/or stay sleeping. Although the effects are generally short-term, this type of insomnia could increase daytime sleepiness, hamper productivity, and result in “brain fog.”
Note: The severity of acute, chronic, and transient insomnia is subject to significant individual variation. One person with an acute case of insomnia may only be getting 3-4 hours of sleep per night, whereas a person with chronic insomnia may be getting 7 hour of sleep per night, but may still feel impaired.
11 Specific Subtypes of Insomnia
The International Classification of Sleep Disorders contains a more advanced, thorough listing of specific diagnostic subtypes of insomnia. Certain subtypes may only fit within one of the three major insomnia classifications, while others may be subject to individual variation. An example would be adjustment insomnia, which is commonly considered a form of acute insomnia, but some cases may only be transient, and others could become chronic.
Adjustment insomnia: Those developing insomnia in reaction to a stressor related to some sort of adjustment are said to have “adjustment insomnia.” The stressor must be identifiable, and is commonly related to a person’s social life, environmental changes, or physical health. This is often considered a type of “acute insomnia” that generally doesn’t persist for longer than a month.
When an individual either adapts to the stressor or learns to cope with it, the adjustment insomnia subsides. For a majority of people, an increase in stress is the primary cause. It is possible for adjustment insomnia to become chronic among 15-20% of adults for over one year. Additionally it is considered to be significantly more common among females than males as well as those of older age.
Behavioral insomnia of childhood: This is a type of insomnia that affects children that associate sleep with parental nurturing. When a child is initially born, parents rock them to sleep, sing them lullabies, and are constantly checking on them. After several years, parents may help their children become more independent by letting them sleep on their own.
However, this may result in behavioral insomnia of childhood. A child may have difficulty falling asleep because they are no longer getting the direct parental attention and/or comfort before bed. This may provoke a fear-response, resulting in an inability to fall asleep due to lack of perceived comfort or safety.
Some children may also wake up in the middle of the night, and be unable to fall back asleep (maintenance-insomnia) because their parents aren’t around. In other cases, a “limit-setting” or enforced parental bedtime may result in insomnia when a child refuses to abide by the “bedtime” set from the parents. It is estimated that between 10% and 30% of children experience childhood insomnia.
Idiopathic insomnia: The prominent characteristic of this type of insomnia is that it is persistent with early onset. In some cases, idiopathic insomnia are nearly lifelong in that they begin during infancy or childhood, and never resolve. Certain individuals with idiopathic insomnia may successfully manage or treat their insomnia for short durations, but sustained remission is uncommon.
In addition to early onset and no sustained remission, there are also no logical or explainable causes or factors that could be contributing to the insomnia. This is a rare type of insomnia that is estimated to affect an estimated 0.7% of teens and approximately 1% of young adults. Some speculate that it may have a genetic basis such as polymorphisms of genes responsible for regulating the circadian rhythm.
Insomnia due to medical condition: Those with medical condition-induced insomnia suffer from an inability to sleep or stay asleep due to a diagnosable condition or physiological factors. Despite the fact that insomnia is common among individuals with medical conditions, this specific type of insomnia is only diagnosed when it causes significant distress and/or deserves special recognition from the preexisting condition. It should be noted that this diagnosis isn’t given for cases in which insomnia occurs separately from the particular condition.
It is important to understand that it isn’t diagnosed often among those with normative sleep impairment related to a medical disorder. If a doctor expects that a person will be sleep impaired for awhile as a result of their condition, they aren’t considered to have medical condition insomnia because this will likely improve. However if insomnia is caused directly by a medical condition and becomes excessive – it fits the diagnosis of “insomnia due to medical condition.”
Insomnia due to mental disorder: It is estimated that nearly 3% of the entire population experiences insomnia caused specifically by either a mental illness. Among individuals that have been formally diagnosed with psychiatric disorders (e.g. generalized anxiety), insomnia is extremely likely to occur. Mental disorders may result in abnormal brain activity (brain waves, neurotransmission, regional activation) – which directly causes insomnia.
Examples of psychiatric conditions that may increase likelihood of insomnia include: anxiety disorders, bipolar disorder, depression, post-traumatic stress disorder, and schizophrenia. In many cases it is difficult to distinguish insomnia due to a mental disorder from drug-induced insomnia due to the fact that many drugs used to treat mental disorders can cause insomnia.
Nonorganic (Unspecified): This is considered a temporary diagnosis of insomnia that is made when physical and substance-based causes cannot be pinpointed. A doctor may have ruled out all possible medical causes and substances that may be responsible for a person’s insomnia, so they temporarily diagnose the individual as having “nonorganic, unspecified insomnia.” The diagnosis is given when a person doesn’t meet criteria for any of the other types of insomnia.
Usually a professional will have an initial hunch that the root cause was a mental disorder, various behaviors, or psychological factors. Later this hunch may be confirmed with further testing. Sometimes it may take several months before the specific cause is revealed to a doctor or sleep expert. Only in rare cases is this diagnosis upheld for prolonged durations.
Organic (Unspecified): In the event that a person experiences insomnia that is believed to be caused by a medical condition, physical problem, or exposure to substances, the diagnosis of “organic, unspecified” is given. In this case, the doctor has good reason to think that there is likely something contributing to the person’s insomnia (e.g. a minor physical injury), but cannot pinpoint the specifics. Since the cause is unclear to the medical professional, this diagnosis is used temporarily.
Paradoxical insomnia: This is considered a form of insomnia in which a person complains to a medical professional of “severe” insomnia, despite having little objective evidence for this complaint. Those with paradoxical insomnia may still have insomnia, but it is much less of an objective problem than as subjectively reported by individuals. Batteries of sleep tests may reveal that a person is getting significantly more sleep than they were able to recall.
In some cases, it could be argued that paradoxical insomnia may be a form of pseudo-insomnia in that an individual may actually be getting sufficient sleep, yet report an inability to sleep. This isn’t considered to be done intentionally, but there are no signs of sleep impairment nor cognitive impairment following the purported “severe” insomnia.
This type of insomnia stems from an inaccurate recall of the amount of time that a person actually slept the previous night. Those with actual insomnia tend to have significantly greater daytime impairment than those with paradoxical insomnia. Treatment for paradoxical insomnia is different in that those with it need to be compassionately shown that they are getting more sleep than they thought and that their performance hasn’t suffered.
Psychophysiological insomnia: Those with psychophysiological insomnia tend to have high levels of arousal and learned “sleep-preventing” associations. The heightened arousal may be related to cognitive, emotional, or physiological processes – resulting in rapid thinking (beta waves), increased environmental awareness, and an inability to turn off their sympathetic nervous system. Most cases of psychophysiological insomnia result from sleep-related anxiety or worry, which either perpetuates or exacerbates the existing insomnia.
Think of this as going to bed, but being anxiously fixated on the fact that you might not get enough sleep. As a result of sympathetic overactivation, you then start worrying about whether lack of sleep will make you fail a test or perform poorly at work, and before you know it, you’re up for several more hours than necessary. You’re unable to shut off the excess mental chatter because you keep worrying about existing insomnia or poor sleep quality.
Sleep hygiene insomnia: This is a type of insomnia that manifests as a result of poor sleeping habits. Those that don’t make an effort to sleep in a comfortable bed, block out bright light, and loud noise should be considered to have poor sleep hygiene. Additionally individuals that don’t adhere to a sleep schedule or are constantly staying up too late to use the computer, TV, or cell phone may have sleep hygiene-insomnia.
Think of this type of insomnia as someone either consciously or unknowingly engaging in activities that compromise their sleep. It is estimated that nearly 2% of teenagers and young adults experience this type of insomnia, and up to 10% of individuals that visit sleep clinics.
Substance-induced insomnia: Anyone using drugs, alcohol, caffeine, (or even supplements), that disrupts a person’s ability to fall asleep or stay asleep may have drug-induced insomnia. The drugs a person is taking could be over-the-counter, pharmaceutical prescriptions, or illicit. Regardless of what drug you’re taking, if it keeps you awake and impairs your ability to sleep, you may be experiencing substance-induced insomnia.
Individuals that frequently use stimulatory substances in the latter half of the day (i.e. afternoon or night) may experience insomnia. In most cases, the insomnia subsides as soon as the individual stops using the substance that is causing it. That said, insomnia may also occur as a result of drug withdrawal, which is something to keep in mind.
- Source: http://www.aasmnet.org/resources/factsheets/insomnia.pdf
- Source: http://www.aasmnet.org/Resources/clinicalguidelines/040515.pdf
What specific type of insomnia do you have?
If you have insomnia and were formally diagnosed by a medical professional, feel free to share the general classification (e.g. chronic) as well as the specific type of insomnia (e.g. substance-induced) that you were diagnosed with. If you haven’t been formally diagnosed, but suffer from insomnia, feel free to mention whether you think you fit any specific type better than the others. Keep in mind that if you suspect you have insomnia and it is causing significant impairment, it should be recommended to seek the help of a trained sleep expert.