Sleep disturbances and suicide risk: A review of the literature (Rebecca A. Bernert and Thomas E. Joiner)

A growing body of research indicates that sleep disturbances are associated with suicidal ideation and behaviors. This article (1) provides a critical review of the extant literature on sleep and suicidality and (2) addresses shared underlying neurobiological factors, biological and social zeitgebers, treatment implications, and future directions for research. Findings indicate that suicidal ideation and behaviors are closely associated with sleep complaints, and in some cases, this association exists above and beyond depression. Several cross-sectional investigations indicate a unique association between nightmares and suicidal ideation, whereas the relationship between insomnia and suicidality requires further study. Underlying neurobiological factors may, in part, account for the relationship between sleep and suicide. Serotonergic neurotransmission appears to play a critical role in both sleep and suicide. Finally, it remains unclear whether or not sleep-oriented interventions may reduce risk for suicidal behaviors. Unlike other suicide risk factors, sleep complaints may be particularly amenable to treatment. As a warning sign, disturbances in sleep may thus be especially useful to research and may serve as an important clinical target for future suicide intervention efforts.
Keywords: suicidality, sleep, nightmares, suicide risk factors

The side effects from missing sleep.
The side effects from missing sleep.

Suicide is a leading cause of death. Approximately 30,000 people die by suicide each year in the United States alone (Murphy 2000). Suicide kills more Americans annually than homicides, and although rates vary substantially by age, suicide ranks as the 11th most common cause of death. Attempted suicides are believed to far exceed this number. It is estimated that 10 to 25 nonlethal suicide attempts occur for every completed suicide (Maris 2002). Moreover, such attempts are responsible for more than 400,000 emergency room visits annually (Doshi et al 2005). Taken together, suicidal behaviors represent a complex, yet potentially preventable public health problem, with far-reaching personal and societal consequences. Improvements in the identification of risk factors for suicidal behaviors thus ultimately enhance our ability to intervene and prevent death by suicide.

The Dangers of Sleep Deprivation.
The Dangers of Sleep Deprivation.

Acute and chronic suicide risk is associated with social, psychological, and biological variables (Lewinsohn et al 1996; Mann et al 2001; Rowe et al 2006), and such factors are often further divided into precipitating and predisposing causes (Mann 2002). One growing area of research includes the study of sleep complaints and suicidality. Increasing evidence suggests that disturbances in sleep are associated with an elevated risk for suicidal behaviors. Both sleep disorders and general sleep complaints appear to be linked to greater levels of suicidal ideation and depression, as well as both attempted and completed suicide (Krakow et al 2000; Agargun et al 1997a; Fawcett et al 1990). In consideration of these findings, sleep problems and more specifically, significant changes in sleep, are now listed among the top 10 warning signs of suicide from the Substance Abuse and Mental Health Services Administration (SAMSHA) (National Mental Health Information Center 2005).

Interestingly, this is the mindset that ascetical texts encourage a monk to acquire, though it is labelled differently, "lowliness of mind," "self-reproach," "remembrance of death,"  "dispassion," etc.
Interestingly, this is the mindset that ascetical texts encourage a monk to acquire, though it is labelled differently, “lowliness of mind,” “self-reproach,” “remembrance of death,” “mourning,” “dispassion,” etc.

Clinical and epidemiological investigations of self-reported sleep disturbances and suicidal behaviors
Poor sleep quality, insomnia, and hypersomnia

Though sleeping schedules differ from monastery to monastery, it averages from 4-5 hrs sleep before vigil (if one actually can fall asleep right away). And 2-3 hours after vigil.
Though sleeping schedules differ from monastery to monastery, it averages from 4-5 hrs sleep before vigil (if one actually can fall asleep right away). And 2-3 hours after vigil.

Fawcett and colleagues conducted one of the first studies to prospectively examine sleep, depression, and suicide (Fawcett et al 1990). In a group of depressed patients, symptoms of global insomnia were more severe among those who completed suicide within a 13-month period. This finding suggested that insomnia may be considered a clinical indicator of acute suicidal risk, perhaps particularly when it appears in the midst of a depressive episode. Agargun et al (1997a) demonstrated a similar link between suicidality, depression, and sleep complaints. Depressed subjects suffering from either hypersomnia or insomnia showed significantly higher scores on measures of suicidality. In a separate study, these authors also examined self-reported sleep quality among depressed patients (Agargun et al 1997b). Subjective sleep quality was significantly more disturbed among suicidal versus nonsuicidal patients.

Types of Sleep Disorders.
Types of Sleep Disorders.

An association between poor sleep quality and completed suicide has been prospectively studied in several community samples of men and women. Among a large group of elderly participants, for example, poor self-reported sleep quality was linked to suicide within 10 years. Although depression showed the strongest link with suicide, poor sleep quality increased the risk for suicide by 34% (Turvey et al 2002). A recent investigation conducted in Japan demonstrated similar findings. Fujino et al (2005) showed that, among 13,259 middle-aged adults, only difficulty maintaining sleep at baseline, compared to other sleep disturbances (eg, difficulty initiating sleep, nonrestorative sleep), significantly predicted death by suicide 14 years later. In both of these studies, depression was not accounted for when examining the association between sleep and completed suicide. Such information would elucidate whether sleep disturbance stands alone as a risk factor for completed suicide or, conversely, whether such sleep complaints simply vary with increased depressive symptoms.

Suicide risk factors.
Suicide risk factors.

Similar to insomnia symptoms, nightmares are more common among suicidal versus nonsuicidal individuals with major depression. Research indicates that depressed patients with self-reported repetitive and frightening dreams are more likely to be classified as suicidal, compared to those without frequent nightmares (Agargun et al 1998). A similar relationship recently emerged in a prospective, population-based study conducted in Finland. Tanskanen et al revealed an association between nightmare frequency at baseline and completed suicides at follow-up 14 years later (Tanskanen et al 2001). Compared to subjects reporting no nightmares, those reporting occasional nightmares were 57% more likely to die by suicide. Among those with frequent nightmares, the risk for suicide increased dramatically; those endorsing frequent nightmares were 105% more likely to die by suicide compared to those reporting no frightening dreams.

Monsters don't sleep under your bed, they sleep in your head.
Monsters don’t sleep under your bed, they sleep in your head.

Bernert and colleagues (2005) investigated the frequency and severity of nightmare symptoms, depression, and suicidality among 176 clinical outpatients using several validated symptom inventories. Results indicated that nightmares predicted elevated suicidal ideation, and this effect was independent of depression. Although this relationship emerged as a nonsignificant trend (p = 0.06), these findings suggest that nightmares may constitute a unique risk factor for elevated suicidality. More recently, Agargun and colleagues (2007) examined nightmare frequency, insomnia symptoms, and suicide attempt status among depressed patients with and without melancholic features. Depressed patients with melancholic features (N = 100) were compared to depressed patients without these features (N = 49). Participants were categorized further as having a history or no history of suicide attempts. Results revealed that melancholic patients with a history of suicide attempts showed higher rates of nightmares and insomnia symptoms compared to melancholic patients without a history of attempts. This study did not assess sleep variables using objective sleep tests; however, it is perhaps the first investigation to examine melancholic depression, suicidality, and sleep disturbances. The authors theorized that feeling worse in the morning as opposed to later in the day, a hallmark symptom of melancholic depression, may be associated with dream content, more negative affect, and in this way, greater risk for suicidality.

Many monks and nuns frequently experience this contradiction.
Many monks and nuns frequently experience this contradiction.

The entire paper can be read here:

Sleep Deprivation and Disease - Effects on the Body, Brain and Behavior.
Sleep Deprivation and Disease – Effects on the Body, Brain and Behavior.

The recent publication of Sleep Deprivation and Disease – Effects on the Body, Brain and Behavior is also an useful research manual:

Geronda Ephraim use to read WWII strategy books to help him understand the art of war. The US  military has recently published manuals on Combat Stress, Sleep Deprivation & Suicide.
Geronda Ephraim use to read WWII strategy books to help him understand the art of war. The US military has recently published manuals on Combat Stress, Sleep Deprivation & Suicide.

As well, Combat Stress (FM 6-22.5) Sleep Deprivation, Suicide Prevention, a manual published by the U.S. Army, U.S. Military, Department of Defense, is also of interest in this subject. It is well known that Geronda Ephraim read WWII battle strategy books while he was on Mount Athos, “to help him understand the strategies of warfare.” If monks are soldiers in a heavenly army, and are in ceaseless battle until their last breath, perhaps manuals about suicide and sleep deprivation applied to physical and earthly warfare may also help:


What Is the Connection Between Sleep Deprivation and Hallucinations?

Sleep deprivation and hallucinations are connected because not getting enough sleep can lead to these figments of imagination. The reason why sleep deprivation and hallucinations are connected isn’t really clear. Some experts think it is simply a symptom of the brain being overtaxed. These hallucinations can be fairly extreme. People may see things that aren’t there or hear sounds that don’t really exist.
Two prominent cases of sleep deprivation and hallucinations being connected can be found in the stories of Randy Gardner and Peter Tripp, who have both held the world record for going without sleep at different times. Both men eventually suffered from severe hallucinations and even lost their ability to reason or think clearly at times. In the case of Peter Tripp, many experts think that his brain was damaged in some way by the experience, causing his personality to change for the worse. Less extreme cases of sleep deprivation can also lead to hallucinations, although usually not as severe ones.

In 1959, Peter Tripp made a record breaking 201-hour wakeathon!
In 1959, Peter Tripp made a record breaking 201-hour wakeathon!

Some people may even experience total psychotic episodes where they lose all grasp of reality. To reach this level of severity usually takes several days without sleep. For less extreme cases, a person may just hear a sound or glimpse something out of the corner of the eye.
Besides the connection between sleep deprivation and hallucinations, there are also several other health risks from not getting enough sleep. It can potentially lead to an increased risk of diabetes, for example, and it can make a person more prone to catching sicknesses. Some people may suffer with anger problems and have their personal relationships threatened. For some individuals, it can even lead to long-term mental issues like depression.

The effects of sleep deprivation.
The effects of sleep deprivation.

Over time, a lack of sleep can greatly limit a person’s cognitive abilities in many different areas, and this can be a problem in almost any kind of career.
When someone is suffering with sleep deprivation, doctors have a lot of options available. In many cases, patients may be prescribed some kind of sleeping medication. For other people, it is simpler to just make a few lifestyle changes. It is possible to become dependent on sleeping medications, especially if they are used for a long time, and they can also be dangerous when mixed with other substances like alcohol. Many physicians will avoid prescribing them if possible.
What Is the Connection Between Sleep Deprivation and Depression?

Sleep-deprived participants showed larger amygdala responses, and their amygdalas showed weaker functional connectivity with medial prefrontal cortex.
Sleep-deprived participants showed larger amygdala responses, and their amygdalas showed weaker functional connectivity with medial prefrontal cortex.

Many experts believe that sleep deprivation and depression can go hand in hand. Disrupted or dysfunctional sleep can lead to feelings of physical fatigue, cognitive impairment, and depressed mood. Conversely, feelings of depression can make it difficult to fall asleep or stay asleep. Often, disorders that cause sleep impairment, such as restless legs syndrome (RLS) or sleep apnea, can cause depressive symptoms. People suffering from depression often experience an improvement in sleep quality once they receive treatment, and people suffering from sleep disorders may experience enhanced mood if treatment is able to improve their sleep quality.
Patients with depressive symptoms are often carefully screened for disorders that can disrupt sleep, and patients with sleep problems are often tested for depression. Disturbed sleep is considered one of the most definitive symptoms of depression, but physical conditions and psychological stress can cause disturbed sleep as well. Sometimes, a patient’s sleep deprivation and depression are so closely intertwined that doctors can’t determine which one came first.
Chronic sleep deprivation and depression can often occur together because sleep deprivation can make people moody, snappish, and unhappy. These symptoms can mimic depression so closely that many may be misdiagnosed with a depressive disorder when, in fact, they are suffering from a sleep disorder.

Hypnagogic Hallucinations - Sleep Cycle
Not everyone who suffers chronic sleep deprivation becomes depressed. Physicians typically believe, however, that adequate sleep is crucial to good physical and mental health. The feelings of physical and mental fatigue brought on by chronic sleep deprivation can make it hard for people with insomnia to enjoy themselves. Fatigue can make exercise difficult, and lowered activity levels can often exacerbate sleep problems. If the situation becomes severe enough, chronic sleep deprivation can lead to health problems, which can further impact mood, since people who feel physically unwell often feel psychologically unwell as a result.
Not everyone who suffers from a depressive disorder develops insomnia. Some people who suffer depressive disorders sleep more than is considered normal. In general, any abnormality with sleep is considered a possible symptom of depression.
Sleep deprivation and depression are so closely linked that, often, treating one of these disorders can improve the other. People suffering from depressive disorders often begin to sleep better as treatment relieves their symptoms of depression. This can occur because the feelings of sadness, guilt, anxiety, and helplessness that often accompany depression can make it hard to fall asleep. Many people with depression find themselves lying awake at night, unable to sleep because they can’t relax. By the same token, people struggling with sleep disorders often begin to feel more generally cheerful when they receive treatment and begin to enjoy better sleep.

What Are the Symptoms of Sleep Deprivation?

4 Stages of Hypnagogia.
4 Stages of Hypnagogia.

The symptoms of sleep deprivation include cognitive delays, behavioral changes, and physical symptoms. In the short term, a patient may find it difficult to function. Long-term sleep deprivation can have serious health consequences, including increasing the risk of chronic diseases like diabetes. Treatment is available, and it is important to seek assistance in cases where a patient cannot address sleep deprivation independently.
Cognitively, sleep deprivation can quickly lead to significant changes in neurological function. Patients who are not sleeping well have difficulty concentrating and focusing. They often encounter problems with routine tasks and have delayed reaction times, a particular danger for drivers and heavy equipment operators. Tremors, muscle weakness, and clumsiness are also common symptoms of sleep deprivation. The cognitive symptoms are similar to those seen in patients with high levels of blood alcohol.
Behaviorally, many people with sleep deprivation experience irritability and are often quick to anger. These symptoms of sleep deprivation can be explosive and frustrating for the patient; she may lash out at people around her or grow irritated by relatively minor environmental changes, like a strong smell or the sound of conversations. Sleep deprivation can also increase stress levels and may contribute to depression and anxiety.

Hypnagogic causes
Symptoms of sleep deprivation can also include uncontrolled yawning, joint pain, and bloodshot eyes. Patients may develop appetite changes, eating more or less than usual. Some patients develop nausea and may have difficulty eating or could vomit after eating, especially if the source of the sleep deprivation is stress or anxiety. A sense of heaviness and extreme fatigue is another warning sign of sleep deprivation. Prolonged lack of sleep can lead to dry skin, slower healing of cuts and scrapes, and muscle and joint stiffness.
Treatments for patients showing symptoms of sleep deprivation can include sleep aids to help the patient sleep. Patients may also need to rearrange their schedules, practice better sleep hygiene, and work on eliminating sources of stress. Individuals at risk of losing sleep because of their jobs or studies need to be especially careful during stressful periods like final exams or the days leading up to a product release, as lack of sleep can impede their ability to function effectively. Staying up all night to study, for instance, may actually make a test-taker more prone to mistakes on the examination, while a good night of sleep could help keep the mind sharp and ready for the test.
What is Delayed Sleep Phase Syndrome?

Hypnagogic Hallucinations 1
Just as it sounds, delayed sleep phase syndrome is a disorder occurring when a person regularly cannot fall asleep at his or her desired bedtime. Those who experience this syndrome often take two or more hours to fall asleep, which not only often results in difficulty waking at the desired time but also often results in insufficient amounts of rest. It is considered a debilitating disorder because the sufferers sleep patterns do not adhere to the normal circadian rhythm, which is the body’s biological cycle that normally recurs at 24 hour intervals. Because of the inability to sleep at night, delayed sleep phase syndrome sufferers are often excessively sleepy during the day, which interferes with their work or school.
Symptoms include insomnia, lots of energy during the evening hours, and excessive daytime drowsiness. The effects of delayed sleep phase syndrome include irritability, depression and sleep deprivation. The syndrome differs from insomnia in that patients with delayed sleep phase tend to fall asleep at nearly the same time each night/morning no matter what time they go to bed.
Delayed sleep phase syndrome often begins in adolescence; although some cases begin in the childhood years. It is rare that it starts in someone older than 30. Similar symptoms, but not the syndrome itself, may be triggered by an event like staying up all night studying or partying, or shift work.
Most patients experience restful, sound sleep and wake up normally, as long as they get the appropriate number of hours of sleep. These patients are often described as “night owls” or “night people” due to their alertness and the high level of energy that tends to occur in the later evening and night hours.

Many possible treatments exist for delayed sleep phase syndrome. Exposure to bright light in the early morning hours can be helpful. This light therapy is similar to that used for those with seasonal affective disorder.
Chronotherapy is a process of moving bedtime later by three hours each 24-hour period until a patient reaches his or her desired bedtime. Other patients have found benefits from melatonin or vitamin B12. Patients generally do not find long-term success with going to bed early, employing relaxation techniques or sleeping pills. In fact, the use of sleeping pills can aggravate the daytime drowsiness issues.
Because there is no diagnostic test to determine delayed sleep phase syndrome, a physician will take a patient’s sleep history. A patient should keep a sleep diary so that he or she can provide accurate, long-term information to the physician. Usually the symptoms must persist for at least a month for a diagnosis, but often the symptoms persist much longer.
Also see: Auditory hallucinations in those populations that do not suffer from schizophrenia.