Sleep Deprivation And Mood Disorders
A recent area of research is that of mood disorders and their biological implications. The research looks at both the causal implications, such as genetic predisposition, and therapies that may be used (invasive and non-invasive). Sleep disturbances frequently are tied to mood disorders, often due to unusual circadian rhythms. Sleep disturbances also can “cure” mood disorders in certain cases.
More research is needed to understand all these areas, but the following three studies highlight much of the new information.The first study is Plante and Winkelman’s “Sleep Disturbance in Bipolar Disorder: Therapeutic Implications,” which looks at the scope and range of sleep disturbances in different types of bipolar disorder and ways in which the sleep disturbance may impact the person’s functioning and recovery. After the initial information (background studies), Plante and Winkelman look at the implications of deliberate sleep deprivation in the treatment of depression.They note that since a lack of sleep precedes, causes, or occurs during a manic episode (which opposes depression on a scale of moods), depriving a depression sufferer from sleep may cure or aid the depressive episode.
The hypothesis is that rather than using antidepressants or other means of controlling a depressive state, sleep deprivation may be a reliever. This study is a review of several other studies done, and does not conduct its own experiment. Therefore the procedure is merely to review recently completed studies for clues to how sleep deprivation functions in people with mood disorders.Plante and Winkelman look at sleep deprivation in bipolar people in a manic state quite thoroughly.
There are several chemical means of controlling sleep deprivation and insomnia, including benzodiazepines and lithium, the former being more popular. These treat insomnia in particular. SSRIs (selective serotonin reuptake inhibitors) and anti-depressants are also sometimes used, as are anti-convulsants. One major finding is that although sleep deprivation does appear to alleviate depression in some people, returning to a normal sleep schedule results in a relapse.This is an issue as sleep deprivation therefore appears to be a temporary fix, not a true “cure.
” In some studies Plante and Winkelman quote, very few people (less than 6%) received any real benefit from sleep deprivation, and instead required psychiatric drugs and other, more traditional treatments. Other studies quoted by Plante and Winkelman, however, found that for bipolar patients (as opposed to unipolar depressed people), sleep deprivation was much more effective.They note that if lithium is given to patients during sleep deprivation (a common neuro-biological treatment), patients are less likely to relapse. It was also found that shifting circadian rhythms (such as the time a patient goes to sleep) as well as exposing patients to bright lights in the morning reduced depressive state relapses. There are still limitations on these findings, such as potentially sending patients into a manic state (which Plante and Winkelman discuss early in the literature review; most patients have an apparently decreased need for sleep during manic episodes.
In certain cases decreased sleep precedes manic episodes and appears to cause or exacerbate them. This is one potential problem with sleep deprivation as a therapy for depression in bipolar patients), the feasibility of causing sleep deprivation in patients, and the tendency towards relapse once recovery sleep habits are reestablished. In the conclusion, Plante and Winkelman note that the first priority for psychologists is to control the sleep disturbances in bipolar patients by some means, as sleep disturbances are common and affect mood.Cause and effect cannot truly be established, so a therapist must carefully assess each patient and select from available methods what will work best for individual patients.
Further research into the role of sleep deprivation in bipolar patients is needed. In today’s society of taking drugs to fix many problems, patients can become overmedicated quickly, with depression or mania as a side effect of medication in some cases. To combat this problem, and to establish health in patients without creating chemical dependency, alternative therapies – like sleep deprivation – need more research.Because of the issues with circadian rhythms and light exposure, it is possible (as briefly noted in this study) that if patients are exposed to bright lights (especially in the morning) and have their sleep-wake cycles better regulated, that they may find natural depression alleviation.
More research into working with patients to re-regulate their bodies to more natural rhythms is needed, perhaps with some initial chemical aids. It is fascinating, though, that it may be possible to regulate patients without the use of chemicals in some cases.The second study is “Restricted and disrupted sleep: Effects on autonomic function, neuroendocrine stress systems and stress responsivity,” by Meerlo, Sucheki, and Sgoifo. This study looks at how the body functions under conditions of stress and sleep deprivation, including how the two areas are interrelated. After the introduction, Meerlo, Sucheki and Sgoifo review several studies on the body’s functions under temporary and chronic sleep deprivation.
Small changes to the brain occur in chronic sleep deprivation, because sleep deprived people function with more cortisol and other stress-related hormones.The body is therefore more susceptible to illnesses and other problems. This, like the previous study, is a literature review that looks at several other studies done, and does not have a procedure or participants in particular. Instead, the article carefully looks at the body’s functions in sleep deprivation based on prior research. The purpose of this study is to understand the implications of sleep deprivation on stress functioning within the body, and the potential problems this has on the person.The researchers hypothesize that many common issues – mood disorders and other health problems – are caused by or exacerbated by sleep deprivation, and that in fact, the brain actually changes over time with chronic sleep deprivation.
Interestingly, the authors note that sleep deprivation has immediate effects on the brain’s stress and arousal centers. Sleep deprived brains do not respond the same way non-sleep deprived brains. There is reduced sensitivity to stress hormones. Cognitive processing is slowed. These effects occur after only 3 – 4 days of interrupted or less sleep.
Most of the data comes from animal studies, as there are ethical concerns with subjecting humans to loss of sleep and then forcing them to perform difficult mental or physical tasks. Some studies have looked at humans’ ability to exercise or complete similar strenuous tasks while sleep deprived, and the authors found that people’s brains showed less activity in regions that react to stress hormones. The researchers also noted that depression may be caused or exacerbated by lack of sleep, as changes in sleep habits are highly correlated with mood disorders.More importantly, especially due to this country’s lifestyle of continuous sleep deprivation for a large part of the population, more effects were found in chronic sleep deprivation.
Most studies were done in rats due to ethical concerns. It was found that rats’ sympathetic nervous systems were suppressed to some degree with chronic sleep deprivation. Serotonin production and receptors were also affected. This is a major issue as serotonin regulates sleep habits in normal individuals, so clearly being sleep deprived affecting serotonin is going to perpetuate sleep disturbances and therefore sleep deprivation.REM sleep was particularly important.
The authors note, in conclusion, that chronic sleep deprivation, even slight sleep deprivation, leads to an unusually high sympathetic nervous system, with increases in heart rate and blood pressure. Other issues, according to Meerlo et al. include reduced plasticity of the brain and neural atrophy, which may speed up the process of aging and the possibility of mental disorders. Another concern is that the body would not react appropriately to future stressors because the sympathetic nervous system was in effect all the time, changing the brain’s reaction to the stress hormones.
This could affect the body in times of stress. More research is needed in this area. Unfortunately, ethical concerns make research difficult, but with a population that is extremely sleep deprived, research should be possible. Researchers should select participants who are already sleep deprived, as demonstrated by a questionnaire on sleep habits and/or referrals from doctors. The researchers may then study the group’s overall brain function versus a group of people who are not sleep deprived to note the differences in reaction, especially in stress hormones.It is important to learn the long-term implications of impaired stress functioning.
Meerlo et al. theorizes that many modern issues, including high blood pressure and mood disorders are caused by or exacerbated by sleep deprivation, but the scope of issues affected by sleep deprivation could be much greater. Further research with a human sleep deprived population would give greater insight into other issues. The third and final article is “Circadian genes, rhythms and the biology of mood disorders,” by Colleen McClung.The purpose of this study is to look at the way circadian rhythms affect the development of mood disorders and contribute to other abnormalities. McClung’s hypothesis is that circadian rhythms are highly associated with mood and other disorders.
After the introduction, the McClung explains what the circadian clock is, and what basis it has in mood disorders based on previous studies. McClung notes that most people with mood disorders benefit from going to sleep earlier and rising earlier in the morning, with the light, and that people who are “night owls” are more likely to suffer from mood disorders than are people who are “morning larks. People with impaired circadian rhythms, for whatever reason, generally are predisposed towards mood disorders.McClung theorizes that circadian rhythms and other naturally occurring phenomenon (light/dark) are crucial in helping people to adapt and avoid mood disorders, or become cured from mood disorders.
This study is also a literature review that looks at many effects from disrupted circadian rhythm, and does not have specific participants, nor a specific procedure. McClung looks at several different areas of circadian rhythms, sleep issues and mood throughout the sections of her paper.It is important, according to McClung, to be able to adapt relatively easily to different sleep/wake cycles and other circadian rhythms. People who do not adapt easily are more likely to suffer from mood disorders, such as people who frequently travel or who work the third shift. When a person is out of sync with the environmental rhythms (light/dark) mood disorders are more likely. According to McClung, Seasonal Affective Disorder (SAD) is thought to be caused by unusual circadian rhythms.
Melatonin plays heavily in this disorder, which affects people during the winter months.There is no conclusion yet on whether or not melatonin does or should change seasonably in people; changes have been demonstrated in both normal people and people with SAD, depending on geographic location. McClung’s results concur with the first study that total sleep deprivation can be a cure for depression. She also agrees that shifting the sleep schedule, taking lithium, or bright light therapy may help depression to stay away, rather than returning to sleep causing an immediate relapse. Bright light therapy is another commonly used treatment, according to McClung.
Using the therapy either in the morning or evening will produce a phase shift, either earlier or later, respectively; it is important to know which the patient needs to produce the maximum benefit. McClung’s research shows that light in the blue wavelengths is most effective in suppressing melatonin and changing the circadian clock. Chemically, McClung notes that lithium, SSRIs, anti-depressants, and other drugs may be used to alter circadian rhythms. Lithium is particularly useful in those with rapid-sleep cycle bipolar; it is not very useful in those with unusually slow clocks.Lithium is supposed to have a phase delay, while SSRIs are supposed to have a phase advance, so the proper treatment must be selected carefully.
McClung’s final section describes human predisposition to unusual circadian rhythms. That is, that a person is genetically impaired. Some people with unusual responses to certain genes have been more likely to suffer from depression or bipolar, especially women. Chemical therapy may be helpful for some of these people. Some variations may even reduce reaction to stress, leading to people dealing with stress better in some cases.
McClung’s general conclusion is that there is not much research yet in this field. Generally, McClung’s research looks at the current state of circadian rhythms in mood disorders and responses. People who are more adaptable to changes in their circadian rhythms, and who are not genetically predisposed to have impaired circadian rhythms tend to suffer from fewer mood disorders and have fewer problems than those who are extremely sensitive to changes, or who are genetically predisposed towards having unusual circadian rhythms.Should a person suffer from either a mood disorder or impaired rhythms, using drugs or other therapies may help the person restore normal rhythms and improve functioning. Some people have a phase delay and others have an advanced phase; knowing which is the case will help to prescribe appropriate treatment.
The type of psychiatric medication which is used, and/or the time at which the treatment is administered, it affected by the specific issue the person is having with their internal clock.Seasonal disorders are also caused by these rhythms, as in the winter, when days are shorter and nights are longer, the increased darkness can cause disruptions to the circadian rhythms, therefore affecting mood in certain individuals. More research into combinations of these theories and therapies is needed. It is impossible to tell exactly which course of treatment is best, as it will vary highly from person to person, but researchers should look at human profiles and which treatments generally fit best with these profiles, in order to understand more about their circadian rhythms and how the current therapies may benefit people.More research is also highly needed into the genetic causes of circadian disturbances and how these might predispose people to develop depression or other mood disorders. Further research is needed in all these areas; however, each study presents relevant and consistent facts about current research in sleep, mood disorders, and natural rhythms.