Understanding DSM-5 Diagnostic Criteria for Hypersomnolence Disorder

Hypersomnolence, or excessive sleepiness, is a common sleep disorder that affects a significant portion of the population. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), it is characterized by recurrent episodes of sleep or lapses into sleep during the same day, a prolonged main sleep episode of more than 9 hours per day that does not feel refreshing, and difficulty being fully awake after abrupt awakenings. This disorder is one of the sleep disorders that can interfere substantially with an individual's ability to perform daily activities and maintain a good quality of life.

Symptoms and Diagnostic Criteria

To be diagnosed with hypersomnolence disorder, individuals must exhibit at least three of the following symptoms on at least three days per week over a three-month period:

Recurrent periods of sleep or lapses into sleep within the same day. A prolonged main sleep episode of more than 9 hours per day that is non-restorative. Difficulty being fully awake after abruptly awakening. The hypersomnolence is accompanied by significant distress or impairment in cognitive, social, occupational, or other important areas of functioning. The hypersomnolence is not better explained by or does not occur exclusively during the course of another sleep disorder (e.g., narcolepsy, breathing-related sleep disorder, circadian rhythm sleep-wake disorder, or a parasomnia). The hypersomnolence is not attributable to the physiological effects of a substance (e.g., a drug of abuse, a medication). Coexisting mental and medical disorders do not adequately explain the predominant complaint of hypersomnolence.

Severity Assessment

The severity of hypersomnolence disorder is based on the degree of difficulty maintaining daytime alertness, which can be categorized as mild, moderate, or severe:

Mild: Difficulty maintaining daytime alertness 1-2 days/week. Modate: Difficulty maintaining daytime alertness 3–4 days/week. Severe: Difficulty maintaining daytime alertness 5-7 days/week.

Individuals with this disorder typically exhibit good sleep efficiency (90%) and often have sleep inertia, a period of confusion, ataxia, or impaired motor dexterity upon awakening. This period may last for minutes to hours and can significantly affect daily activities. People with hypersomnolence may also experience automatic behavior, where they perform routine tasks with little or no recall.

Manifestation and Course of the Disorder

Hypersomnolence disorder typically manifests in late adolescence or early adulthood, with a mean age at onset of 17-24 years. It is rare in pediatric cases, and the disorder tends to have a progressive onset, symptoms appearing between ages 15 and 25. The course is usually persistent and stable unless treatment is initiated. The risk of developing other sleep disorders (e.g., breathing-related sleep disorder) can exacerbate sleepiness.

Risk and Prognostic Factors

Several factors can increase the risk of developing hypersomnolence:

Environmental: Psychological stress and alcohol use can temporarily increase the incidence of hypersomnolence. Viral infections, such as HIV, pneumonia, infectious mononucleosis, and Guillain-Barré syndrome, can also trigger hypersomnolence within 6-18 months after the infection. Head trauma can also be a precipitating factor within 6-18 months. Genetic and physiological: Hypersomnolence may have a familial pattern with an autosomaldominant mode of inheritance.

Understanding the diagnostic criteria and factors contributing to hypersomnolence can help in early identification and appropriate management of the disorder, improving the quality of life for affected individuals.