Section 13: Information that Indicates Hypersomnolence Disorder

DSM-5-TR Code: G47.10  Unspecified

DSM-5-TR Code: G47.19  Specified

Common Specifiers:


Common Specifiers:


Common Specifiers (All Types):

Prevalence: 0.005%

Can Insomnia Disorder legitimately be diagnosed by a Master’s level Clinician?      Generally no, as a sleep specialist is usually required in order to rule out other conditions, like Sleep Apnea, that are more likely explanations for this condition.

Hypersomnolence Disorder, as noted by its prevalence, is a rare condition in which the client feels unrestored even after what an average person would experience as a full night’s sleep.  Persons with this disorder may sleep up to 18 hours a day, with nighttime sleep supplemented by frequent naps. Neither the naps nor extended night time sleep appears to reduce the general feeling of sleepiness that the patient experiences

This disorder often begins during adolescence and develops over the course of several years into full-blown hypersomnolence. At this point in time, there is no known cause for this disorder, as the etiological factors have not been fully identified. According to the Hypersomnia Foundation, the most likely explanation is over-production of a molecule that interacts with GABA, a neurotransmitter that is involved in the promotion of sleep. (Hypersomnia Foundation)

There are a number of medical conditions that may create symptoms that mimic this disorder. Hypothyroidism and mononucleosis create metabolically driven fatigue that may cause a client to sleep for longer periods of time. Negative reactions to medications, or substances like alcohol or opioids, or interactive effects between medications and mind altering substances may also create excessive sleepiness. Also, extreme fatigue created by the presence of another kind of sleep disorder must also be ruled out. 

In the unlikely event that a clinician sees a client presenting with signs and symptoms of hypersomnia, a referral should first be made to a primary care physician to rule out medical causes of excessive sleeping, followed by a referral to a sleep specialist if all medical causes have been ruled out.  Treatment may involve the utilization of stimulant medications, so involvement of a physician experienced in working with this disorder will be essential.