The new Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) has a number of changes to sleep disorders, now called sleep-wake disorders. This article outlines some of the major changes to these conditions.
According to the American Psychiatric Association (APA), the publisher of the DSM-5, they sought to increase the clinical utility of this category. “To that end, some conditions that were separate in DSM-IV now are grouped together to help facilitate diagnosis,” says the APA. “Others have been divided based on greater understanding of the pathology triggering certain disorders or their underlying neurobiological and genetic factors.”
The APA also wanted to better capture the dynamic relationship between sleep-wake disorders and certain mental or medical conditions. So they place a greater emphasis on how these disorders can interact and impact each other, because they have been shown to be mutually exacerbating.
DSM-5 underscores the need for independent clinical attention of a sleep disorder regardless of mental or other medical problems that may be present. Two previous diagnoses — sleep disorder related to another mental disorder and sleep disorder related to another medical condition — have been eliminated.
The new chapter also changes the name of primary insomnia to insomnia disorder. This switch is intended to avoid the primary/secondary designation when this disorder co-occurs with other conditions and to reflect changes throughout the classification.
Last, according to the APA, this chapter of sleep disorders — which contains ten conditions — focuses on dimensional assessments as well as categorical assessments for a number of reasons:
Doing so helps clinicians to capture the severity of symptoms and facilitate measurement-based clinical care. Examining these disorders through a dimensional lens also will help to identify behaviors contributing to the genesis or persistence of a condition. Finally, where supported by science and considerations of clinical utility, DSM-5 integrates pediatric and developmental criteria and text for numerous sleep-wake disorders.
DSM-5 pays more attention to co-existing medical conditions when it comes to sleep disorders, to better emphasize when an individual has a sleep disorder warranting independent clinical attention, in addition to any medical and mental disorders that are also present. The APA recognizes that co-existing medical conditions, mental disorders and sleep disorders are interactive and bidirectional in the DSM-5 — it’s not as important to make assumptions about what causes the sleep disorder.
That’s the reason the diagnosis of primary insomnia has been renamed insomnia disorder, in order to avoid the differentiation of primary and secondary insomnia.
DSM-5 also distinguishes narcolepsy — which is now known to be associated with hypocretin deficiency — from other forms of hypersomnolence. These changes, the APA believes, are warranted by neurobiological and genetic evidence validating this reorganization.
Finally, throughout the DSM-5 classification of sleep-wake disorders, pediatric and developmental criteria and text are integrated where existing science and considerations of clinical utility support such integration. This developmental perspective encompasses age-dependent variations in clinical presentation.
Breathing-Related Sleep Disorders
In DSM-5, according to the APA, breathing-related sleep disorders are divided into three relatively-distinct disorders:
- Obstructive sleep apnea hypopnea
- Central sleep apnea
- Sleep-related hypoventilation
This change reflects the growing understanding of pathophysiology of these disorders.
Circadian Rhythm Sleep-Wake Disorders
“The subtypes of circadian rhythm sleep-wake disorders have been expanded to include advanced sleep phase syndrome, irregular sleep-wake type, and non-24-hour sleep-wake type,” according to the APA. The jet lag type has been removed.
Rapid Eye Movement Sleep Behavior Disorder and Restless Legs Syndrome
The use of DSM-IV “not otherwise specified” diagnoses has been reduced by designating rapid eye movement sleep behavior disorder and restless legs syndrome as their own, independent disorders.
Health Consequences and The Importance of Sleep
When a person doesn’t get a good night’s sleep, it has a plethora of health and cognitive consequences:
The most obvious concerns are fatigue and cognitive focus, but mood can be greatly affected, too. A sleep disorder not only is a risk factor for subsequent development of certain mental conditions but a potential warning sign for serious mental or medical issues. For example, sleep disturbances can signal the presence of medical and neurological problems such as congestive heart failure, osteoarthritis, and Parkinson’s disease.
Sleep disorders range from insomnia disorder to narcolepsy and breathing-related disorders to restless legs syndrome. They are diagnosed through comprehensive assessment, which may entail a detailed patient history, physical exam, questionnaires and sleep diaries, and clinical testing. They often are addressed in similarly comprehensive ways involving behavioral, pharmacologic and other treatments in combination with medical care.