Sleep issues are common throughout our lives. Most often they are transient difficulties that come and go uninvited. Sometimes, they are due to changes in our environment, or sleep habits that we picked up along the way. Other times, sleep problems may appear to persist despite our best efforts for no apparent reason – and more often than not, mess with our day, energy, health, and livelihood. This blog will outline the types of common sleep disorders (based on the ICSD-3-TR: International Classification of Sleep Disorders, 3rd ed, text revision), which fall under six major categories:
- Insomnia Disorders
- Circadian Rhythm Sleep-Wake Disorders
- Sleep-Related Breathing Disorders
- Central Disorders of Hypersomnolence
- Parasomnias
- Sleep-Related Movement Disorders
Insomnia Disorders
When asked to think about sleep problems, most people think of early insomnias (i.e., difficulty getting to sleep early in the night – formally termed “sleep initiation” difficulties). However, there are other forms of insomnia. These include difficulty with waking up at night, waking up much earlier than planned, and in the case of younger people (e.g., children) resisting going to bed on prescribed schedules and /or difficulty sleeping without caregiver support. Formal criteria exist to assess the above, was discussed in a previous blog on this site.
Circadian Rhythm Sleep-Wake Disorders
In circadian rhythm sleep-wake disorders, the physiological process that many would call our body clock is out of sync with the environment. In this case, out of sync with the daylight cycle. Why is this important? Have you ever been jet lagged? If you have, then you experienced a temporary circadian rhythm misalignment and its mental and physical effects.
Now, imagine if your internal body clock had to coordinate a different time zone multiple times a week, such as in shift work; or swap zones between weekends and weekdays (e.g., wake up at 6AM every weekday, but 10AM every weekend), for months at a time. Many people would experience undesirable sleep-wake schedules, symptoms of insomnia or excessive sleepiness, and different types of impairment.
The main circadian rhythm sleep-wake disorders are:
- Delayed sleep-wake phase disorder (late patterns of sleep, and waking, times – often more than 2h compared to expected time frames in similar peers)
- Advanced sleep-wake phase disorder (early patterns of sleep, and waking, times – often more than 2h compared to expected time frames in similar peers)
- Irregular sleep-wake rhythm disorder (no clear patterns of sleep, and waking, times; more common in people with conditions of neurodevelopmental / neurological nature)
- Non-24h sleep-wake rhythm disorder (erratic / shifting sleep, and waking, times – often seen in people experiencing prolonged light deprivation, or those with damaged photoreceptors used by our brain to synchronize the circadian system to external light)
- Circadian sleep-wake disorder not otherwise characterized (i.e., not clearly fitting above), or circadian symptoms better attributable to other disorders.
Sleep-Related Breathing Disorders
Sleep-related breathing disorders are complex with strong biological causes. They can be divided in four broad categories:
- Central sleep apnea
- Obstructive sleep apnea
- Sleep-related hypoventilation disorders
- Sleep-related hypoxemia disorders
If you experience symptoms of a sleep-related breathing disorder, you will most likely be referred to a medical professional for further assessment and support. This can involve a visit to a sleep lab and an overnight sleep analysis through a process called polysomnography .
In many cases, people can have one of these conditions and other ones together. For instance, the condition of people with a sleep-related breathing disorder and insomnia is termed COMISA (COMorbid Insomnia & Sleep Apnoea).
Central Disorders of Hypersomnolence
These disorders comprise a set of enduring symptoms. Including strong sleepiness, with an uncontrollable need to nap throughout the day. They are often diagnosed via assessment and elimination of other plausible causes. Additionally, similarly to sleep-related breathing disorders, psychological treatment is often adjunct to core medical support. Some of these disorders are given below:
- Narcolepsy type I & II
- Idiopathic hypersomnia
- Hypersomnia due to another disorder (e.g., psychiatric, medical), or substances / medications
Parasomnias
Parasomnias refer to a family of sleep disorders where the waking and sleeping mind partially intersect. That is, people may be partially awake, but not aware, of these experiences. Such experiences may range from involuntary behaviors in their sleep to vivid and recurring nightmares.
There are three main categories of parasomnias: a) non-rapid eye movement (NREM) related parasomnias; b) rapid eye movement (REM) related parasomnias; and c) other parasomnias. Emerging research is showing more and more that a combination of medical and psychological support may be helpful for people experiencing different types of parasomnias.
Some examples of parasomnias are:
- NREM-related: sleepwalking, sleep terrors, sleep talking (or groaning), confusional arousals
- REM-related: REM sleep behavior disorder, recurrent isolated sleep paralysis, nightmare disorders
- Other parasomnias: sensory parasomnias, sleep-related dissociative disorders, sleep enuresis, sleep-related hallucinations, sleep-related eating disorder, parasomnia due to drug or substance use, parasomnia due to a medical condition
Sleep-Related Movement Disorders
The final main category relates to sleep-related movement disorders, many of which are often addressed by a combination of therapeutic tools. These include cognitive behavioral therapy, stress management skills, & dental interventions in bruxism. The main disorders in this category are:
- Restless Legs Syndrome (RLS): experiencing strong urges to move limbs (most commonly: legs; less commonly: arms + chest) or / and unpleasant sensations (e.g., crawling) while resting, worsening as evening progresses to night, & making it harder to fall asleep – with movement of affected limbs relieving this sensation. May also present alongside PLMD.
- Periodic Limb Movement Disorder (PLMD): people with RLS may also present with a periodic limb movement disorder characterized by: repetitive movements of arms, legs, or feet while asleep. Movements range from a few seconds to several minutes, repeating several times per hour. While these movements may wake people up, disturbing their sleep, they are often noticed/reported by a bed partner.
- Sleep-related Leg Cramps: can be recurring & severe enough to influence sleep in several ways.
- Sleep-related Bruxism: recurring instances of jaw clenching / grinding during sleep, which can lead to pain and dental problems (among other adverse physical health outcomes).
- Sleep-related Rhythmic Movement Disorder: refers to repetitive movements during sleep, or when a person is sleepy, with a predictable / rhythmic pattern (e.g., infants humming, bobbing, rocking). If injuries occur, or sleep and daytime functioning is impaired by the frequency, degree, or intensity of these movements a person may be diagnosed with this disorder.
- And other sleep-related movement disorders.
Concluding Remarks
Getting enough sleep, and of good quality, is important for overall wellbeing and development. Healthcare professionals with expertise in this area can help you explore whether, and to what extent, sleep disorders may be present in your life.
It is important to keep in mind that sleep problems can resolve in different ways. Some sleep complaints may resolve through time. Some through therapy of other difficulties such as the sleep problems associated with anxiety, depression and PTSD. Sleep-wake disorders often require additional support or assessment through your GP, psychologist, or a specialist doctor.
While we may experience sleep difficulties from time to time, specific criteria must be fulfilled to classify them as sleep-wake disorders. Furthermore, there are often other parameters that influence our sleep that are equally important to address. These include, general physical health, psychological difficulties and social circumstances. Thus, while blogs such as this one are helpful to raise awareness about potential sleep problems, they should not be utilized as a substitute for qualified professional guidance.
If you’re struggling with a mental health issue, or a sleep complaint, don’t hesitate to seek help. Book an appointment with our experienced psychologists at the Centre for Clinical Psychology in Melbourne by calling 03 9077 0122. We’re here to support you on your journey to better sleep and mental health.
References
American Academy of Sleep Medicine (2024). International Classification of Sleep Disorders, Third edition, Text Revision (ICSD-3-TR). Retrieved from https://aasm.org/clinical-resources/international-classification-sleep-disorders/
Drakatos, P., Marples, L., Muza, R., Higgins, S., Gildeh, N., Macavei, R., … & Leschziner, G. (2019). NREM parasomnias: a treatment approach based upon a retrospective case series of 512 patients. Sleep Medicine, 53, 181-188.
Judd, B. G., Sateria, M. J. Classifications of sleep disorders. UpToDate. Retrieved June 20, 2024 from https://www.uptodate.com/contents/classification-of-sleep-disorders?search=sleep+disorders&source=search_result&selectedTitle=1%7E150&usage_type=default&display_rank=1
Newsom, R., & DeBanto, J. (2024). Sleep-Related Movement Disorders. Retrieved 20, 2024 from https://www.sleepfoundation.org/sleep-related-movement-disorders#:~:text=According%20to%20the%20International%20Classification,a%20quick%20jerk%20or%20twitch.
