Obesity is a risk factor for OSA.6 Patients with mood disorders or schizophrenia or other psychotic disorders are at higher risk of obesity because of psychotropic-induced weight gain, stress-induced mechanisms, and/or lower levels of self-care. When these patients have unrecognized or untreated OSA and are prescribed sedative medications at night or stimulant medications during the day, they could be at increased cardiac or respiratory risks without resolving their underlying condition. A diligent psychiatrist can dramatically reduce the risks by referring a patient for nocturnal polysomnography,1 helping the patient implement lifestyle modifications (eg, exercise, weight loss, and healthy nutrition), prescribing judiciously, and monitoring closely for such risks. An accurate diagnosis of and treatment for OSA can improve sleep6 dramatically and help depressive symptoms through better sleep, more daytime energy and concentration, and adequate oxygenation of the brain while sleeping.
Psychiatrists can screen for OSA using the STOP-Bang (Snoring, Tired, Observed apnea, Pressure, Body mass index, Age, Neck circumference, Gender) Questionnaire, which is a quick, 8-item screening scale that helps to categorize OSA risk as mild, moderate, or severe.12 Hypertension, snoring, and/or gasping for breath (“observed apnea”)—a history which often is provided by spouses or significant others—daytime dozing and/or tiredness, having a large neck circumference or volume, body mass index, male sex, and age are items on the STOP-Bang Questionnaire and also are features that should raise high clinical suspicion of OSA.12 Referral for nocturnal polysomnography in at-risk patients should be the next step1,5 in any sleep-related breathing disorder.
Treatment for OSA involves continuous positive airway pressure (CPAP) therapy, which has been shown to relieve OSA and decrease related EDS.5,6 Other treatment modalities, such as oral appliances and surgery, may be used5 in some cases, but more studies are needed for conclusive results.
Several studies have shown improved depression, mood, and cognition after administering treatment such as CPAP6,9,14 in patients with OSA and depression. Considering the significant risks of cardiovascular,8 cerebrovascular,8 and overall morbidity and mortality associated with untreated OSA,12 it is important to routinely screen for sleep-disordered breathing in patients with depression9 or other psychiatric disorders and refer for specialized sleep evaluation and treatment, when indicated.
Medications. EDS can result from some prescription and over-the-counter medications.1,2,5,7 Sedating antidepressants, antihistamines, antipsychotics, anticonvulsants,1,8 and beta blockers2 could cause sedation, which can persist during daytime, although a few studies did not find an association between antipsychotic use and EDS.3 Benzodiazepines and other sedative-hypnotics,1,7 especially long-acting agents or higher dosages,5 can lead to EDS and decreased alertness. Non-psychotropics, such as opioid pain medications,1,7 antitussives, and skeletal muscle relaxants, also can contribute to or cause daytime sedation.7 When using these agents, psychiatrists should monitor and routinely assess patients while aiming for the lowest effective dosage when feasible.
This strategy creates a framework for psychiatrists to routinely educate patients about these commonly encountered side effects, reduce polypharmacy when possible, and help patients effectively manage or prevent these adverse effects.
Depression.1 Some studies found >45% patients with depression had EDS.3,13,15 Besides an association between depression and EDS,13,16 Chellappa and Araújo13 also found a significant association between EDS and suicidal ideation. The causes of EDS in patients with depression may be varied, ranging from restless legs syndrome, residual depressive symptoms,15 to OSA. Depression is often comorbid with OSA,6 with up to 20% of patients with depression suffering from OSA,10 creating higher risk for EDS. Depressive disorders are routinely assessed during an evaluation of OSA at sleep centers, but OSA often is not screened in psychiatric practice.10
There is a strong need for regular screening for OSA in patients with depression, particularly because most studies show a link between the 2 conditions.10 Both depression and OSA have some common risk factors, such as obesity, hypertension, and metabolic syndrome.10 Patients with these conditions are at greater risk for OSA, and therefore a psychiatrist should proactively screen and refer such patients for nocturnal polysomnography when they suspect OSA. Patients with OSA and depression often present to the psychiatrist with depressive symptoms that appear to be resistant to pharmacological treatment,10 therefore underscoring the importance of screening and ruling out OSA in patients with depression.
Circadian rhythm disorders, restless legs syndrome, alcohol and other substance use, and use of prescription sedative-hypnotics are more common in patients with depression; therefore, this population is at high risk for EDS.
Circadian rhythm disorders and insufficient sleep syndrome. Insufficient sleep syndrome1,2,8 frequently causes EDS and occurs more commonly in busy people who try to get by with less sleep.8 Over time, the effect of sleep loss is cumulative and can be accompanied by mood symptoms, such as irritability, fatigue, and problems with concentration.8 Shift workers1,8 commonly experience insufficient sleep as well as circadian rhythm disorders and EDS. Modafinil is FDA-approved for EDS in shift work sleep disorder.
Geriatric patients may experience advanced sleep phase syndrome involving early awakenings.8 Adolescents, on the other hand, often suffer from delayed sleep phase syndrome, which is a type of circadian rhythm disorder, related to increasing academic and social pressures, natural pubertal shift to later sleep onset, pervading technology use, and often nebulous bedtime routines. This can be a cause of sleep persisting into daytime.8 Taking a careful history and a sleep diary may be useful because this disorder might be confused for insomnia. Treatment involves gradual shifting of the time of sleep onset through bright light exposure and other modalities.8
Adolescents might not be forthcoming about the severity of their sleep problems; therefore, psychiatrists should screen proactively through clinical interviews of patients and parents and consider this possibility when encountering an adolescent with recent-onset attention or cognitive difficulties.
Treatment for circadian rhythm disorders usually includes planned or prescribed sleep scheduling, timed light exposure,8 and occasional use of melatonin or other sedative agents.17
Hypersomnia of central origin, which includes narcolepsy, idiopathic hypersomnia, and recurrent hypersomnia, can present with EDS.1,18,19 Narcolepsy is a rare, debilitating sleep disorder that manifests as EDS or sleep attacks, with or without cataplexy, and sleep paralysis.5,8,18,19 The Multiple Sleep Latency Test and polysomnography are used for diagnosis.1,5 Shortened REM latency is a classic finding often noted on polysomnography. Treatment involves pharmacologic and behavioral strategies and education.5,8 Modafinil is FDA-approved for EDS associated with narcolepsy. Stimulant medications have been used for narcolepsy in the past; further studies are needed to establish benefit–risk ratio of use in this population.18
Kleine-Levin syndrome is a form of recurrent hypersomnia, a less common sleep disorder, characterized by episodes of excessive sleepiness accompanied by hyperphagia and hypersexuality.5,18,19