“A good day starts with a good night sleep”
Mansoor Ahmed, M.D.
“We may not have a clear understanding of the functions of sleep, but its importance and its impact on our daytime mood and mental functionality becomes apparent when we actually don’t sleep! Or have a disturbed sleep. More than any other specialty, there is a profound link between sleep, cognition and psychiatry. This may be due to the fact that cognition, mood and sleep-wake share many structural mechanistic pathways. Sleep disturbances are in fact so common in psychiatric illnesses that they are considered to be an integral component of diagnostic criteria for many these conditions. Furthermore, as compared to general population, co-morbid Sleep disorders, such Obstructive Sleep Apnea (OSA), Restless legs Syndrome (RLS) and Circadian Rhythm Disorders appear to be more common in patients with psychiatric conditions. These sleep disorders have serious multi-system consequences, including mental health and cognitive symptoms. If remain unrecognized and untreated, these disorders may result in further worsening of sleep and psychiatric conditions. Recognition of the fact that the sleep is important for mental health and that the sleep disturbances are fairly common in patients with psychiatric disorders, a close collaboration between sleep and psychiatric healthcare providers is critical for optimum management of these conditions”.
Interest in behavior, sleep and dreaming has existed since the dawn of the history. From Hippocrates, Aristotle to Freud, and many other greatest thinkers have attempted to unravel the mechanism of sleep and psychological basis of dreaming. The most important of all discoveries related to sleep was the recognition that sleep is not simply a uniform state of unresponsiveness as it was thought for centuries.
In 1953-55, Dr Nathaniel Klietman and his fellow, Dr Charles Dement, demonstrated sleep as a cyclic phenomenon alternating between non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. REM sleep also known as paradoxical or active sleep, when EEG pattern shows an active mind, while body muscles are temporarily paralyzed. Much earlier Freud also noted muscle paralysis during sleep, that hindered the dreamer from acting out their dreams. REM sleep appears to play an important role in memory consolidation and affect regulation including emotional tone related to the past events. NREM sleep is divided into light sleep and slow wave sleep also known as delta sleep. Slow wave sleep appears to play a role in recuperation of CNS and certain memory domains .
The discovery of REM and NREM sleep in 1953 was the beginning of the ‘modern era’ of sleep research and sleep medicine as a discipline. It is becoming clear that sleep medicine is truly a multidisciplinary science. There is hardly any medical, mental or psychiatric condition that doesn’t affect sleep and there is hardly any system physiology that is not affected by sleep and sleep disorders. For example, in OSA repeated disturbances in gas exchange, autonomic system changes and sleep fragmentation that accompany apnea affect multiple physiological systems leading to metabolic, cardio-vascular abnormalities and neuro-psychiatric symptoms. A significant majority of patients evaluated at sleep clinic exhibit frequent symptoms of psychopathology, which may or may not be due to psychiatric illness. Research and clinical evidence concerning the association of sleep disorders with psychiatric problems is growing quickly. Sleep is now recognized by the psychiatrists and psychologists as the neurobiological substrate for many emotional and behavioral disorders. Even a simple loss of sleep (i.e. sleep restriction) can trigger maniac episodes in vulnerable patients with underlying bipolar mood disorders. Conversely, sleep restriction under proper circumstances, has been shown to improve mood in patients with depression. Data from a large number of studies examining neurobiological mechanisms provide strong evidence that sleep, circadian rhythm control and mood share many common neuro-circuitries and neurotransmitters. This may explain the fact that several psychiatric disorders have prominent sleep symptoms.
Not only that sleep disturbances such as insomnia and non-restorative sleep are quite common in many psychiatric disorders, but may actually precede the development and diagnosis of a psychiatric disorder. Furthermore, studies have shown that the presence of persistent sleep disturbances such as insomnia despite apparent improvement in underlying primary psychiatric condition. The presence of persistent insomnia in patients with major depression, receiving treatment, have a poor prognostic value including an increased risk of suicide.
Despite the fact that sleep disorders are common, with profound negative implications on psychiatric illnesses, sleep disorders may remain undiagnosed, despite the relative ease of diagnosis in many cases.
On many occasions, physicians who have exhausted all routine laboratories and medical interventions in an effort to diagnose and treat a patient with undiscovered sleep problems refer the patient to a psychiatrist. In a study by Mosko and colleagues, 66.5% of 206 patients evaluated at sleep center reported one episode of major depression in the previous 5 years and 25.7% described themselves as depressed on presentation. Additional studies have established substantial risk of developing major depression and generalized anxiety in patients with sleep disorders.
Despite strong mechanistic and clinical links between sleep and psychopathology, current clinical practices of both sleep medicine and psychiatry lack optimal collaboration. Also it is only in 1996 the American Medical Association recognized sleep medicine as a specialty. Perhaps this may also explain a lack of delay in clinical integration between sleep, psychiatry and other medical disciplines. A close integration is therefore, very much needed to optimize the clinical care of patients who have either underlying primary sleep or psychiatric disorder.
The following material briefly summarizes the clinical data on the nature of sleep disturbances in psychiatric disorders This review also provides some practical basic guidelines on how to recognize presence of common Sleep Disorders and the beneficial role of appropriate sleep therapies on mood and psychiatric symptoms. The effects of psychotherapeutic agents on sleep are beyond the scope of this review and readers are referred to other excellent review articles on this topic.
A: Primary Psychiatric & Behavioral Disorders and its effects on sleep and daytime wakefulness
B: Common Sleep Disorders and its implications on mood-psychiatric illness
A: Primary Psychiatric & Behavioral Disorders and sleep
1: Sleep in Anxiety disorders
Anxiety disorders are among the most common of mental disorders. Majority of the patients, with General Anxiety Disorder (GAD) (44%), Post Traumatic Stress Disorder (PTSD) and panic (61%) disorders suffer from Insomnia. Difficulty falling or maintaining sleep or non restorative sleep, are one of the six features to establish the diagnosis of GAD. Furthermore, daytime irritability and fatigue can be considered a consequence of sleep disturbances.
Patients with panic disorders have poor sleep efficiency and reduced total sleep time. Panic attacks emerging from sleep (during NREM) are reported in 50% of patents.
PTSD patients suffer from a myriad of severe sleep problems characterized by insomnia and nightmares. PSG evaluation usually reveals fragmented sleep, frequent arousals and reduced slow wave sleep. REM sleep abnormalities may include increased REM sleep latency, disrupted REM sleep continuity and higher REM density including increased eye movement frequency. Abnormal behavior during sleep such as shouting, yelling and dream enactment is commonly observed. Nightmares, predominantly emerging from REM sleep, occur in up to 90% of PTSD patients. These nocturnal sleep disturbances may also contribute to daytime somatic symptoms
Besides the underlying psychiatric conditions and associated changes in sleep-arousal mechanisms, other unrelated, sleep disorders including Restless Legs Syndrome and Periodic Leg Movements during Sleep (PLMS) and circadian misalignment can further contribute and aggravate pre-existing sleep disturbances in these individuals.
It is important to note that certain Selective Serotonin Receptor Inhibitors (SSRI) and Serotonin Norepinephrine Receptor Inhibitors (SNRI) commonly used to treat anxiety disorders, can also contribute to the pathogenesis of RLS/PLMS conditions. Similarly, underlying OSA can result in sleep maintenance insomnia. Some studies have shown an increased incidence of OSA in patients with PTSD. Ironically under these circumstances, utilization of hypnotics, a common clinical practice, may not have any effect on insomnia and may even aggravate it.
On many occasions, maladaptive cognitive behavior such as fear of insomnia provokes bedroom anxiety, may further exacerbate insomnia. Many of these patients also develop the habit of looking at the clock repeatedly further aggravates underlying anxiety and frustration, as well as insomnia.
2: Mood Disorders
Major depression and Bipolar disorders are prevalent and associated disability is one of the highest reported for any disease, second only to ischemic cardiac disease. These disorders are commonly associated with sleep disturbances and these disturbances are part of the diagnostic criteria.
In a majority of the patients with mood disorders, insomnia and sleep disturbance may precede for years before the diagnosis of depression is established. Furthermore, subjective and objective sleep disturbance such as the REM parameters may persist even during a period of clinical remission and herald poor prognosis.
Although insomnia is the most common symptom, hypersomnolence sometimes manifests itself as a symptom of depression. Cyclic insomnia and hypersomnolence can be a clue to underlying bipolar mood disorder. Objective sleep evaluation by PSG has been studied more extensively than any other psychiatric disorder and most patients have shown non-specific objective changes.
The sleep parameters changes include: 1) Disturbed sleep continuity including delayed sleep onset, frequent awakening and early morning awakening; 2) reduced slow wave sleep; and 3) REM sleep abnormalities, particularly reduced REM latency and increased REM density i.e. increased rate of rapid eye movement during REM sleep. There may be evidence that duration of depressive episode may correlate with the degree of observed sleep abnormalities.
Schizophrenia is a disorder of thought and cognitive impairment and considered as the most devastating neuropsychiatric illness. Underlying sleep disturbances can be severe and include profound insomnia, and reversal of sleep-wake cycle. Clinically stable patient on treatment may continue to have early and middle of the night insomnia. Sleep architecture in those patients is characterized by poor sleep efficiency and difficulty in achieving persistent sleep. Unlike depression, no specific abnormalities in REM sleep have been found in schizophrenia these patients.
4: Attention Deficit Hyperactivity Disorder (ADHD)
Insomnia is frequently reported in ADHD. Besides sleep disturbances related to ADHD, other comorbid conditions can result in insufficient and poor quality sleep, such as OSA, RLS, and Delayed sleep phase syndrome (DSPS), potentially aggravating the ADHD symptoms.
It is of utmost importance to carefully tease out the potential problems affecting sleep before confirming or rejecting the diagnosis of ADHD. Sleep disturbances disrupts the attention and arousal mechanisms, presumably by perturbations in neurotransmitter pathways, notably noradrenergic and dopaminergic pathways. Successful implementation of strategies to address the underlying issues causing sleep disturbances help with the improvement in sleep and potentially helps with the daytime neurobehavioral symptoms.
B: Primary Sleep Disorders and relationship to mood-psychiatric illness
There are more than 80 recognized sleep disorders. Many of these sleep disorders are associated with a higher incidence of anxiety and depression. Some common sleep disorders such as OSA, RLS and Circadian Disorders appear to be more prevalent in patients with psychiatric conditions. These sleep disorders have serious multi system consequences including mental health and cognitive symptoms. If remain unrecognized and untreated, these disorders may result in further worsening of sleep and psychiatric conditions”
Sleep apnea is a serious and most common sleep disorder affecting 12 million American. Majority of the OSA sufferers remain undiagnosed. This condition is far more common in obese individuals with hypertension, particularly resistant hypertension, diabetes and congestive heart failure. In general, OSA is characterized by loud snoring and repeated episodes of breathing cessation during sleep resulting in sleep fragmentation and non-restorative sleep. The resulting daytime consequences include: a) sleepiness, fatigue, other neuro-cognitive abnormalities; b) increased risk of hypertension and stroke; and c) metabolic abnormalities.
Patients with depression as well as OSA appear worse off than those with OSA only. Depressive symptoms persist in at least some patients in short term studies of treatment for OSA. Direct treatment of depression in OSA might improve acceptance of therapy, reduce sleepiness and fatigue and improve quality of life
OSA: Important facts
• An estimated 12 million Americans suffer from sleep-disordered breathing.
• Sleep apnea causes daytime sleepiness in an estimated 1 out of 25 (4 percent) middle aged men and 1 out of 50 (2 percent) middle aged women.
• Up to 93 percent of women and 82 percent of men with signs and symptoms of moderate to severe sleep-disordered breathing remain undiagnosed.
• The symptoms of sleep-disordered breathing (such as snoring) are more likely to be reported by men than women.
• Women are much more likely to develop sleep apnea after menopause.
• African Americans, Hispanics, and Pacific Islanders are more likely to develop sleep apnea than Caucasians.
• The risk of sleep apnea increases with age. At least 1 out of 10 people over the age of 65 suffers from sleep apnea.
• More than half of people with sleep apnea are overweight.
2. Restless Leg Syndrome and Periodic Leg Movement Disorder
Sleep disturbance due to RLS and PLMS can lead to daytime sleepiness, anxiety or depression, and confusion or slowed thought processes. PLMS always coexists with RLS, but may occur independent of RLS. Most often RLS occurs in middle aged and older adults. Idiopathic RLS can occur at a young age as well. RLS is always more severe during in the evening hours and at night, in more severe cases, can also occur during daytime. Other common symptoms include: creepy crawly sensations in legs (arms and whole body can be involved) with an urge to move; usually when sitting or lying down; moving legs or walking relieves the symptoms at least temporarily.
Once diagnosed, treatment for the condition is available and can be very effective.
3. Circadian Rhythm Disorders
These disorders are commonly termed as disruptions in internal biological clock. Such disruption can either be advanced or delayed phase. In Delayed Sleep Phase Disorder (DPSD), where the sufferers are also called “Night Owls,” are unable to sleep until very late in the night or early morning hours. DPSD is more common in children and adolescents. Whereas, those with Advanced Sleep Phase Disorder (ASPD) fall asleep in the early evening hours, resulting in early morning awakening as early as midnight to 2 a.m. ASPD is more commonly seen in the elderly.
In both situations, the circadian mismatch can have a negative impact on school and work performance, as well as social consequences.
4. Narcolepsy and other sleep disorders of hyper-somnolence
Although Narcolepsy is not a common sleep disorder, but can be extremely debilitating for the sufferers. Same can be said about hypersomnia, whether it the result of narcolepsy or due to other sleep disorders or underlying psychiatric disorders.