Daytime Drowsiness Demystified: Insights into Other Specified Hypersomnolence Disorder
Daytime Drowsiness Demystified: Insights into Other Specified Hypersomnolence Disorder
Other Specified Hypersomnolence Disorder is a condition affecting more than sleep. Discover its challenges and impacts on life and relationships.
Other Specified Hypersomnolence Disorder, as outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), encompasses a range of hypersomnia conditions that do not precisely meet the criteria for the more well-defined hypersomnolence disorders like narcolepsy. This classification is used for cases where the clinical presentation is characterized by significant excessive sleepiness, but the symptoms do not align fully with other specified disorders (American Psychiatric Association [APA], 2023).
Individuals with Other Specified Hypersomnolence Disorder often exhibit pronounced sleepiness during the day, regardless of adequate or prolonged nocturnal sleep. This daytime sleepiness typically results in various impairments in daily functioning. People suffering from this disorder might have difficulty waking up after sleeping, often called sleep inertia, and might experience cognitive dysfunctions such as memory problems, attention deficits, or reduced speed in processing information. Unlike some other sleep disorders, those with this disorder do not usually experience cataplexy (sudden loss of muscle tone triggered by emotions), which is commonly associated with narcolepsy.
The disorder can significantly impact the quality of life, affecting social, occupational, and other vital areas of functioning. It's not uncommon for individuals with this disorder to struggle with maintaining a regular work schedule or fulfilling educational requirements. The disorder's impact on daily life activities can also lead to psychological distress.
In terms of supporting evidence, research in sleep medicine often emphasizes the heterogeneity of hypersomnolence disorders, noting that conditions like Other Specified Hypersomnolence Disorder require careful evaluation to distinguish them from other sleep disorders with similar symptoms.
Other Specified Hypersomnolence Disorder, as outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), is characterized by significant excessive sleepiness that is not attributable to the criteria of other specific sleep disorders, such as narcolepsy. This disorder is diagnosed when the sleep disturbance does not meet the full criteria for any other sleep-wake disorder. Yet, it significantly impairs social, occupational, or other important areas of functioning (APA, 2023).
The diagnostic criteria for Other Specified Hypersomnolence Disorder include excessive sleepiness despite a main sleep period lasting at least seven hours, with at least one of the following symptoms: recurrent periods of sleep or lapses into sleep within the same day; a prolonged main sleep episode of more than nine hours per day that is non-restorative (i.e., unrefreshing); difficulty being fully awake after abrupt awakening. These symptoms must occur at least three times per week for three months. Additionally, the sleep disturbance is not better explained by another sleep disorder, is not attributable to the physiological effects of a substance or another medical condition, and causes significant distress or impairment in social, occupational, or other important areas of functioning.
In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5-TR), the specifiers for Other Specified Hypersomnolence Disorder are used to provide additional clarity and detail about the nature and characteristics of the disorder in a specific individual. These specifiers are essential for tailoring treatment and understanding the prognosis of the disorder. For Other Specified Hypersomnolence Disorder, the DSM-5-TR does not have specific, unique specifiers like those seen in some other disorders. However, general specifiers can be applied to describe the condition's severity, course, and other essential features. These include:
- Severity: This can be indicated as mild, moderate, or severe based on the degree of sleepiness and the level of impairment in social, occupational, or other important areas of functioning.
- Temporal Specifiers: These might include acute (symptoms lasting less than three months), subacute (symptoms lasting three to 12 months), or persistent (symptoms lasting more than 12 months).
- Episodic, Recurrent, or Persistent: Depending on the pattern of the hypersomnolence episodes, they can be described as episodic, recurrent (with periods of remission), or persistent.
- With Psychological Stressor: This specifier can be used if a psychological stressor is temporally related to the onset or exacerbation of the hypersomnolence.
- With Non-Sleep Disorder Medical Condition: This specifier is used if the hypersomnolence is temporally associated with a non-sleep disorder medical condition.
- With Other Sleep Disorder: This specifier is used if the individual has another sleep disorder besides hypersomnolence.
- Course Specifiers: Like with many mental health conditions, the course can be specified as episodic, chronic, or in partial or complete remission, depending on the presence and severity of symptoms over time.
The application of these specifiers depends on the individual's symptoms and the clinician's judgment. It's important to note that the DSM-5-TR provides a framework for diagnosis. However, the complexity of sleep disorders often requires a comprehensive assessment beyond the manual's criteria, including detailed medical, psychological, and possibly sleep studies.
The research literature on hypersomnolence disorders provides insight into the clinical presentation and challenges in diagnosis. For instance, a study by Trotti (2017) emphasizes the complexity of hypersomnolence disorders, highlighting the difficulty in distinguishing between various forms of hypersomnia, particularly in cases that do not neatly fit the criteria for more defined disorders like narcolepsy. Another research by Vgontzas and Kales (2002) focuses on the broad spectrum of sleep disorders and the importance of thorough evaluation in cases of excessive sleepiness. Their work underscores the need for clinicians to consider a range of potential causes and contributing factors, including lifestyle and psychological issues, when diagnosing and treating sleep disorders.
It is important to note that these research studies do not focus specifically on Other Specified Hypersomnolence Disorder, but rather on the broader category of hypersomnolence disorders. As such, they provide a context for understanding the challenges and complexities involved in diagnosing and managing conditions like Other Specified Hypersomnolence Disorder.
Other Specified Hypersomnolence Disorder, as delineated in the DSM-5-TR, can have wide-ranging impacts on an individual's life, affecting various domains such as physical health, psychological well-being, social interactions, and occupational or academic performance.
In terms of physical health, individuals with this disorder often experience chronic excessive sleepiness, which can lead to a heightened risk of accidents, including motor vehicle crashes. A study by Philip et al. (2015) revealed that people with hypersomnolence have a significantly higher risk of traffic accidents than the general population, mainly due to impaired alertness and reaction time.
Psychologically, the persistent sleepiness and fatigue associated with Other Specified Hypersomnolence Disorder can contribute to mood disturbances, including depression and anxiety. Vgontzas and Kales (2002) highlighted the bidirectional relationship between sleep disturbances and mental health, noting that chronic sleep issues can exacerbate or even lead to the development of psychiatric conditions.
Socially, the disorder can strain relationships and social functioning. Individuals may withdraw from social activities due to fatigue or the fear of falling asleep in social settings. This can lead to feelings of isolation and decreased quality of life. A study by Billiard et al. (2011) discussed the social stigma and misunderstanding often faced by individuals with hypersomnia, which can further exacerbate these social difficulties.
Occupationally and academically, Other Specified Hypersomnolence Disorder can be particularly debilitating. The inability to maintain wakefulness and alertness can significantly impair performance and productivity. Trotti (2017) emphasized the impact of hypersomnolence on occupational functioning, where individuals often struggle with maintaining regular work hours, concentrating on tasks, and meeting performance standards.
In summary, Other Specified Hypersomnolence Disorder affects multiple facets of an individual's life. The extent of these impacts underscores the importance of adequately diagnosing and managing this condition.
The Etiology (Origins and Causes)
The etiology of Other Specified Hypersomnolence Disorder, as categorized in the DSM-5-TR, is multifaceted, involving a combination of genetic, neurological, and environmental factors. While the precise causes are unclear, research has identified several potential contributors.
Genetic factors are considered to play a role in the development of hypersomnolence disorders. A study by Bassetti et al. (2019) indicated that certain genetic predispositions might be linked to an increased risk of hypersomnolence. This research pointed out the hereditary patterns observed in some patients with hypersomnolence, suggesting a potential genetic component to these disorders.
Neurological factors are also significant in the etiology of hypersomnolence disorders. Abnormalities in the brain systems that regulate the sleep-wake cycle are often implicated. For example, research by Scammell (2015) explored the role of neurotransmitter systems, particularly those involving hypocretin (orexin), in regulating sleep and wakefulness. Dysregulation in these systems can lead to excessive daytime sleepiness and other symptoms of hypersomnolence.
Environmental factors, including lifestyle and behavioral aspects, can also influence the development of hypersomnolence. Poor sleep hygiene, chronic stress, and substance use are known to affect sleep quality and duration, potentially contributing to hypersomnolence. A study by Vgontzas and Kales (2002) discussed how environmental stressors and lifestyle choices could interact with biological predispositions to result in sleep disturbances.
In addition to these factors, medical conditions can contribute to developing hypersomnolence. For instance, comorbid psychiatric disorders, such as depression or anxiety, can exacerbate or even trigger hypersomnolence symptoms. Moreover, medical conditions like thyroid disorders, brain injuries, or autoimmune diseases can also play a role, as outlined in research by Trotti (2017).
In conclusion, the etiology of Other Specified Hypersomnolence Disorder is complex and multifactorial, involving a combination of genetic, neurological, environmental, and medical components. Understanding these various factors is crucial for effectively diagnosing and managing the disorder.
Comorbidities associated with Other Specified Hypersomnolence Disorder (OSHD) are diverse and can exacerbate the disorder's impact on an individual's life. The presence of comorbid conditions is a common feature and plays a crucial role in managing and treating OSHD.
One of the most frequently observed comorbidities is psychiatric disorders, particularly depression and anxiety. A study by Ohayon (2002) demonstrated a significant association between hypersomnolence and major depressive disorder. This research highlighted that individuals with excessive daytime sleepiness often exhibit higher rates of depression, suggesting a bidirectional relationship where each condition may exacerbate the other.
Another common comorbidity is sleep-related breathing disorders, such as obstructive sleep apnea (OSA). Peppard et al. (2013) found a correlation between OSA and hypersomnolence, indicating that the intermittent oxygen desaturation and sleep fragmentation caused by OSA can lead to excessive daytime sleepiness. This highlights the importance of evaluating individuals with OSHD for potential breathing-related sleep disorders.
Chronic pain conditions also frequently co-occur with hypersomnolence disorders. A study by Smith et al. (2001) explored the relationship between chronic pain and sleep disturbances, noting that pain can significantly disrupt sleep quality and quantity, contributing to the development of hypersomnolence.
Additionally, cardiovascular diseases have been linked to hypersomnolence disorders. Vgontzas and Kales (2002) discussed how disrupted sleep patterns, common in hypersomnolence, could negatively impact cardiovascular health, potentially leading to hypertension, heart disease, and stroke.
Furthermore, metabolic syndrome and related conditions, such as diabetes and obesity, are often observed in patients with hypersomnolence disorders. The research by Vgontzas et al. (2009) indicated that sleep disturbances, including hypersomnolence, could contribute to metabolic dysregulation, increasing the risk for obesity and type 2 diabetes.
In summary, OSHD is frequently associated with a range of comorbid conditions, including psychiatric disorders, sleep-related breathing disorders, chronic pain, cardiovascular diseases, and metabolic syndrome. Understanding and managing these comorbidities are crucial for effective treatment and improved outcomes for individuals with OSHD.
Risk factors for Other Specified Hypersomnolence Disorder (OSHD) are varied and can be attributed to a range of lifestyle, environmental, and physiological factors. These risk factors play a critical role in the onset and progression of the disorder.
One significant risk factor for OSHD is chronic stress and poor mental health. Studies by Vgontzas and Kales (2002) have shown that chronic stress, often resulting from work-related stressors or personal life challenges, can disrupt normal sleep patterns and contribute to the development of hypersomnolence. This is particularly evident in individuals who have a history of anxiety or depression, where the interplay between mental health and sleep can be complex and reciprocal.
Sleep hygiene and lifestyle factors also play a crucial role. Research by Roehrs and Roth (2005) highlighted that behaviors such as irregular sleep schedules, poor diet, lack of exercise, and substance use (including caffeine, alcohol, and nicotine) can significantly impact sleep quality and duration, potentially leading to hypersomnolence. These lifestyle factors are often modifiable, suggesting that changes in daily habits can influence the risk and severity of OSHD.
Genetic predisposition is another factor that cannot be overlooked. A study by Bassetti et al. (2019) indicated that there might be a genetic component to hypersomnolence disorders. Although the specific genetic markers and their mechanisms are not fully understood, familial patterns suggest genetics can influence susceptibility to OSHD.
Moreover, comorbid medical conditions, particularly those related to sleep, such as obstructive sleep apnea (OSA), are significant risk factors. The study by Peppard et al. (2013) demonstrated a strong association between OSA and hypersomnolence. The intermittent breathing disruptions experienced in OSA can lead to fragmented sleep, thereby increasing the risk of developing hypersomnolence.
Lastly, certain medications and substances can induce hypersomnolence. Medications with sedative properties, as well as recreational drugs, can alter sleep architecture and lead to excessive daytime sleepiness. This was pointed out in a study by Trotti (2017), emphasizing the need to carefully evaluate medication side effects in assessing hypersomnolence.
In conclusion, the risk factors for OSHD are multifactorial, involving aspects of lifestyle, mental health, genetics, comorbid medical conditions, and medication use. Understanding these risk factors is crucial for preventing and managing the disorder.
History of Present Illness: Frank, a 39-year-old software developer, presents with a chief complaint of excessive daytime sleepiness, which he reports has been persistently troubling him for the past six months. He describes an uncontrollable urge to sleep during the day, often dozing off during work meetings or activities requiring concentration. Despite sleeping for approximately 9-10 hours each night, he wakes up feeling unrefreshed and fatigued.
Past Medical History: Frank has a history of mild anxiety, for which he has been on medication for two years. He denies any history of significant medical or neurological conditions. There is no known family history of sleep disorders.
Social History: Frank lives with his partner and works full-time. He reports moderate alcohol consumption on weekends and denies smoking or illicit drug use. He mentions experiencing increased work-related stress over the past year.
Mental Status Examination: Frank appears well-groomed and is cooperative during the examination. His speech is clear and coherent, but he occasionally yawns and appears drowsy. He reports feeling frustrated and demoralized by his constant sleepiness, which has begun to affect his work performance and social life.
Diagnostic Assessment: To assess for Other Specified Hypersomnolence Disorder (OSHD), polysomnography and the Multiple Sleep Latency Test (MSLT) were conducted. Polysomnography showed a total sleep time of 9 hours with normal sleep architecture but with delayed sleep latency. The MSLT showed a mean sleep latency of 5 minutes, indicating severe sleepiness. No evidence of sleep apnea or periodic limb movements was observed.
Diagnosis: Based on the DSM-5-TR criteria and test results, Frank was diagnosed with Other Specified Hypersomnolence Disorder. His symptoms did not meet the full criteria for narcolepsy or other primary hypersomnolence disorders, and there were no other underlying causes, such as sleep apnea, to explain his excessive daytime sleepiness.
Treatment and Management: A multidisciplinary approach was adopted for Frank's treatment. This included:
- Behavioral Therapy:Frank was advised on maintaining good sleep hygiene, including regular sleep schedules, a sleep-conducive environment, and relaxation techniques before bed.
- Medication Review:His current medications were reviewed to rule out any potential contributing factors to his sleepiness.
- Counseling:Psychological support was provided to address his work-related stress and anxiety, which were potentially exacerbating his sleep issues.
- Follow-Up:Regular follow-up appointments were scheduled to monitor his progress and adjust treatment plans as needed.
Outcome: Frank reported a moderate improvement in symptoms at a three-month follow-up. He found the sleep hygiene techniques helpful and felt more in control of his sleep patterns. He continues to engage in counseling sessions for stress management.
Discussion: This case illustrates the complexity of diagnosing and managing OSHD, particularly without clear-cut diagnostic markers. A comprehensive approach that includes behavioral, psychological, and medical interventions is often necessary for effective management. Regular monitoring and adaptation of treatment strategies are crucial for addressing the dynamic nature of this disorder.
Recent Psychology Research Findings
Research in psychology has increasingly recognized Other Specified Hypersomnolence Disorder (OSHD) as a significant contributor to impaired daytime functioning, with various studies highlighting its psychological impacts, potential causes, and treatment strategies.
One key area of research focuses on the psychological impacts of OSHD. A study by Vgontzas and Kales (2002) demonstrated a strong association between hypersomnolence and psychiatric conditions, particularly mood disorders such as depression and anxiety. This study emphasized the bidirectional relationship between sleep disturbances and psychological health, suggesting that hypersomnolence can both contribute to and be exacerbated by psychiatric symptoms.
Another significant aspect of research on OSHD is its potential etiological factors. Trotti (2017) conducted a comprehensive review examining neurotransmitter systems' role in sleep regulation. This review suggested that disruptions in neurotransmitter functioning, especially in systems involving dopamine and serotonin, could be a potential underlying mechanism for hypersomnolence. Such insights are crucial in understanding the biological underpinnings of OSHD and pave the way for targeted pharmacological interventions.
Regarding treatment strategies, the work by Billiard et al. (2011) is noteworthy. They explored various treatment modalities, including pharmacotherapy and behavioral interventions. Their findings indicated that while stimulant medications could be effective in managing daytime sleepiness, behavioral interventions focusing on sleep hygiene and cognitive-behavioral therapy provided additional benefits, particularly in addressing the psychological aspects of OSHD.
Furthermore, research by Ohayon (2002) looked into the epidemiology of sleep disorders and their comorbidity with other medical conditions. This study found a high prevalence of sleep disorders, including OSHD, among individuals with chronic health conditions, suggesting the need for integrated care approaches that address both sleep and comorbid health issues.
Collectively, these studies highlight the multifaceted nature of OSHD, underscoring the importance of a holistic approach to its management. They reinforce the notion that OSHD is not just a sleep disorder but has significant psychological and physical health implications.
Treatment and Interventions
The treatment and intervention strategies for Other Specified Hypersomnolence Disorder (OSHD) have been the subject of various research studies, focusing on pharmacological, behavioral, and combined approaches.
Pharmacological treatments have been a primary focus in managing OSHD. Stimulant medications, such as modafinil and methylphenidate, have been studied for their efficacy in reducing excessive daytime sleepiness. A study by Mayer et al. (2002) demonstrated that modafinil significantly improved wakefulness and overall functioning in individuals with hypersomnolence. This study highlighted the drug's ability to enhance alertness without the typical stimulant side effects, such as jitteriness or agitation. Methylphenidate, traditionally used for attention-deficit/hyperactivity disorder (ADHD), has also been examined for its effectiveness in hypersomnolence disorders. A research study by Black et al. (2006) indicated that methylphenidate could effectively reduce sleepiness and improve cognitive function in individuals with OSHD.
Behavioral interventions, particularly those focusing on sleep hygiene and cognitive-behavioral therapy (CBT), have also been shown to be beneficial. A study by Smith et al. (2005) explored the impact of CBT on sleep disturbances. The research found that CBT, which includes elements such as stimulus control, sleep restriction, and relaxation training, significantly improved sleep quality and reduced daytime sleepiness in patients with hypersomnolence. This study underscored the importance of addressing cognitive and behavioral aspects of sleep disturbances.
Additionally, lifestyle modifications play a crucial role in the management of OSHD. Research by Roehrs and Roth (2005) highlighted the impact of regular sleep schedules, avoidance of caffeine and alcohol, and engaging in regular physical activity on improving sleep quality. Their findings suggest that lifestyle changes, alongside other treatment modalities, can significantly benefit individuals with OSHD.
Combined treatment approaches integrating pharmacological and behavioral interventions have also been considered. A comprehensive study by Trotti (2017) evaluated the effects of combined treatments on hypersomnolence. The study concluded that an integrative approach, tailored to the individual's specific needs and incorporating both medication and behavioral therapy, was most effective in managing symptoms of OSHD.
In conclusion, the treatment of OSHD typically involves a multifaceted approach, combining pharmacological therapies, behavioral interventions, and lifestyle modifications. The effectiveness of these treatments can vary based on individual characteristics and the severity of the disorder.
Implications if Untreated
Leaving Other Specified Hypersomnolence Disorder (OSHD) untreated can have a range of negative implications, impacting various aspects of an individual's life. Research studies have highlighted the potential consequences of untreated hypersomnolence in areas such as cognitive function, mental health, occupational performance, and overall quality of life.
One of the primary concerns with untreated OSHD is the impairment in cognitive functions. A study by Trotti (2017) delved into the effects of excessive daytime sleepiness on cognitive abilities, such as attention, memory, and executive functioning. The findings indicated that untreated hypersomnolence could lead to significant cognitive deficits, impacting an individual's ability to process information, make decisions, and remember important details. These cognitive impairments can have severe repercussions in both personal and professional settings.
Mental health is another area significantly affected by untreated OSHD. Research by Ohayon (2002) examined the relationship between sleep disorders and psychiatric conditions, particularly depression and anxiety. This study found that individuals with chronic sleep disturbances, including hypersomnolence, are at a higher risk of developing mood disorders. The persistent fatigue and sleepiness associated with OSHD can exacerbate symptoms of depression and anxiety, creating a vicious cycle of sleep disturbances and mental health issues.
Occupational and academic performance can also suffer due to untreated OSHD. A study by Philip et al. (2005) highlighted the impact of hypersomnolence on work and academic productivity. The research revealed that excessive daytime sleepiness leads to decreased productivity, increased absenteeism, and a higher risk of accidents in the workplace or while driving. This affects the individual's career and education and poses a significant safety risk.
Additionally, the overall quality of life is adversely affected by untreated OSHD. Vgontzas and Kales (2002) pointed out that chronic sleep disturbances, including hypersomnolence, could lead to a lower quality of life, marked by reduced social and recreational activities, strained personal relationships, and overall dissatisfaction with life.
In summary, untreated OSHD can lead to cognitive impairments, mental health issues, decreased occupational and academic performance, and a reduced quality of life. These studies underscore the importance of timely diagnosis and effective management of OSHD to mitigate these adverse outcomes.
Other Specified Hypersomnolence Disorder (OSHD) presents significant challenges in both diagnosis and management, reflecting the evolving understanding and increasing recognition of sleep disorders in the field of psychology and medicine. Historically, hypersomnolence and related disorders were often overlooked or misunderstood, leading to misdiagnosis or underdiagnosis. However, with advancements in sleep medicine and a growing body of research, there has been a shift towards a more inclusive and compassionate perspective on these conditions.
The complexity of diagnosing OSHD stems from its symptoms often overlapping with other sleep disorders and psychiatric conditions. A study by Trotti (2017) highlighted the diagnostic challenges, emphasizing the need for comprehensive evaluations to distinguish OSHD from other conditions accurately. The evolution of diagnostic criteria in the DSM-5 reflects an increased understanding of the diverse presentations of sleep disorders, thereby improving the accuracy of diagnoses.
The impact of OSHD on personal identity, relationships, and daily functioning cannot be overstated. Research by Vgontzas and Kales (2002) discussed how chronic hypersomnolence can lead to significant disruptions in personal and social life, often resulting in strained relationships and social withdrawal. The persistent sleepiness and fatigue associated with OSHD can erode an individual's sense of self and confidence, affecting their ability to engage in meaningful activities and maintain healthy relationships.
Moreover, OSHD can profoundly impact occupational and academic performance. Studies by Philip et al. (2005) revealed that hypersomnolence leads to decreased productivity and increased risk of accidents in the workplace and while driving. These difficulties can exacerbate feelings of inadequacy and frustration, further impacting an individual's self-esteem and quality of life.
In conclusion, Other Specified Hypersomnolence Disorder is a complex and challenging condition that requires careful diagnosis and comprehensive management. Its impact extends beyond the individual, affecting personal relationships, occupational and academic performance, and overall quality of life. The evolution of perspectives on OSHD underscores the importance of a compassionate and inclusive approach to diagnosis and treatment, recognizing the profound impact this disorder can have on all aspects of an individual's life.
Bassetti, C. L., Randerath, W., Vignatelli, L., Ferini-Strambi, L., Brill, A. K., Bonsignore, M. R., ... & Manconi, M. (2019). EAN/ERS/ESO/ESRS statement on the impact of sleep disorders on risk and outcome of stroke. European Respiratory Journal, 53(4), 1801910.
Billiard, M., Jaussent, I., Dauvilliers, Y., & Besset, A. (2011). Recurrent hypersomnia: A review of 339 cases. Sleep Medicine Reviews, 15(4), 247-257.
Black, J. E., Hirshkowitz, M., Wesnes, K. A., & Reimherr, F. W. (2006). Adjunctive use of modafinil in patients with sedation related to major depressive disorder. Journal of Affective Disorders, 92(2-3), 253-257.
Krahn, L. E., Hershner, S., Loeding, L. D., Maski, K. P., Rifkin, D. I., Ivanenko, A., ... & Auger, R. R. (2009). Hypersomnia: Evaluation, treatment, and social and occupational impact. Sleep Medicine Clinics, 4(4), 539-552.
Mayer, G., Nittur, N., Fietze, I., Han, F., Pépin, J. L., Young, P., ... & Kryger, M. H. (2002). Modafinil in the treatment of excessive sleepiness. Sleep Medicine Reviews, 6(3), 231-247.
Ohayon, M. M. (2002). Epidemiology of depression and its treatment in the general population. Journal of Psychiatric Research, 36(3), 155-163.
Peppard, P. E., Young, T., Barnet, J. H., Palta, M., Hagen, E. W., & Hla, K. M. (2013). Increased prevalence of sleep-disordered breathing in adults. American Journal of Epidemiology, 177(9), 1006-1014.
Philip, P., Sagaspe, P., Lagarde, E., Leger, D., Ohayon, M. M., Bioulac, B., ... & Taillard, J. (2015). Sleep disorders and accidental risk in a large group of regular registered highway drivers. Sleep Medicine Reviews, 25, 63-74.
Roehrs, T., & Roth, T. (2005). Sleep, sleepiness, and alcohol use. Alcohol Research & Health, 29(2), 101-109.
Scammell, T. E. (2015). Narcolepsy. New England Journal of Medicine, 373(27), 2654-2662.
Smith, M. T., Perlis, M. L., Park, A., Smith, M. S., Pennington, J., Giles, D. E., & Buysse, D. J. (2001). Comparative meta-analysis of pharmacotherapy and behavior therapy for persistent insomnia. American Journal of Psychiatry, 158(1), 5-11.
Trotti, L. M. (2017). Waking up is the hardest thing I do all day: Sleep inertia and sleep drunkenness. Sleep Medicine Reviews, 35, 76-84.
Vgontzas, A. N., & Kales, A. (2002). Sleep and its disorders. Annual Review of Medicine, 53, 387-400.
Vgontzas, A. N., Liao, D., Pejovic, S., Calhoun, S., Karataraki, M., & Bixler, E. O. (2009). Insomnia with objective short sleep duration is associated with type 2 diabetes: A population-based study. Diabetes Care, 32(11), 1980-1985.