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|Alma mater||University of Louisville School of Medicine ,|
Yale School of Medicine
|Known for||Seasonal affective disorder, |
Major depressive disorder
|Institutions||National Institute of Mental Health|
Thomas Alvin Wehr scientist emeritus at the National Institute of Mental Health is a psychiatrist, research scientist, author, and former chief of the Clinical Psychobiology branch at NIMH.
The National Institute of Mental Health (NIMH) is one of 27 institutes and centers that make up the National Institutes of Health (NIH). The NIH, in turn, is an agency of the United States Department of Health and Human Services and is the primary agency of the United States government responsible for biomedical and health-related research.
A psychiatrist is a physician who specializes in psychiatry, the branch of medicine devoted to the diagnosis, prevention, study, and treatment of mental disorders. Psychiatrists are medical doctors, unlike psychologists, and must evaluate patients to determine whether their symptoms are the result of a physical illness, a combination of physical and mental ailments, or strictly psychiatric. A psychiatrist usually works as the clinical leader of the multi-disciplinary team, which may comprise psychologists, social workers, occupational therapists and nursing staff. Psychiatrists have broad training in a bio-psycho-social approach to assessment and management of mental illness.
A scientist is someone who conducts scientific research to advance knowledge in an area of interest.
Wehr received his degree in medicine from the University of Louisville School of Medicine in 1969. He subsequently completed his psychiatric residency at Yale School of Medicine and his internship was at Michael Reese Hospital.
The University of Louisville is a public university in Louisville, Kentucky, a member of the Kentucky state university system. When founded in 1798, it was the first city-owned public university in the United States and one of the first universities chartered west of the Allegheny Mountains. The university is mandated by the Kentucky General Assembly to be a "Preeminent Metropolitan Research University". The university enrolls students from 118 of 120 Kentucky counties, all 50 U.S. states, and 116 countries around the world.
The Yale School of Medicine is the graduate medical school at Yale University in New Haven, Connecticut. It was founded in 1810 as The Medical Institution of Yale College, and formally opened in 1813.
Michael Reese Hospital and Medical Center was an American hospital located in the Bronzeville neighborhood of Chicago, Illinois. Founded in 1881, Michael Reese Hospital was a major research and teaching hospital and one of the oldest and largest hospitals in Chicago, Illinois. It was located at 2929 S. Ellis Avenue on the near south side of Chicago, next to Lake Shore Drive which lies along Lake Michigan. The hospital closed its Internal Medicine Residency at the end of the 2007-2008 academic year and finished transferring patients to Mercy Hospital and Medical Center before the end of 2008. The 48-acre campus was then vacated by January 2009 and calls to the main number were greeted by: "We're sorry. All circuits are busy now. Please try your call again later." From 2007 to its closing, Michael Reese had been owned by Envision Hospital Corporation of Scottsdale, Arizona. The hospital officially closed August 31, 2009. At one time, the hospital had a large health plan which included 300,000 patients; at the time of the hospital's closure the health plan was terminated and it only had 2,900 clients. The streets through the campus were closed and demolition began in October 2009.
In a 1990s study on photoperiodicity in humans, –but across two separate blocks, not unbroken. First, subjects tended to lie awake for one to two hours and then fall quickly asleep. Onset of sleep was linked to a spike in the hormone melatonin. Melatonin secretion by the brain's pineal gland is triggered by darkness. After an average of three to five hours of sleep, the subjects would awaken and spend an hour or two in quiet wakefulness before a second three- to five-hour sleep period. It was thus suggested that such a biphasic pattern of sleep is the natural or pre-historic tendency for humans.Wehr placed a group of volunteers in an environment in which it was dark for 14 hours each day for a month. The subjects were able to sleep as much as they wanted during the experiment. The first night, the subjects slept an average of 11 hours a night. This was judged as probably repaying a chronic sleep debt. By the fourth week, the subjects slept an average of eight hours a night
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue.
Melatonin is a hormone that regulates sleep–wake cycles. It is primarily released by the pineal gland. As a supplement, it is often used for the short-term treatment of trouble sleeping such as from jet lag or shift work. Evidence of benefit, however, is unclear. One review found onset of sleep occurred 6 minutes faster with use but found no change in total time asleep. It may work as well as the medication ramelteon. It is typically taken by mouth.
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycles. The shape of the gland resembles a pine cone from which it derived its name. The pineal gland is located in the epithalamus, near the center of the brain, between the two hemispheres, tucked in a groove where the two halves of the thalamus join. The pineal gland is one of the neuroendocrine secretory circumventricular organs that are not part of the blood-brain-barrier.
No research into the sleeping patterns in natural environments of primates closely related to humans was cited for comparison.
Wehr and colleague Norman E. Rosenthal are credited with identifying and describing Seasonal Affective Disorder (SAD) and developing light therapy to treat it.
Norman E. Rosenthal is a South African author, psychiatrist and scientist who in the 1980s first described winter depression or seasonal affective disorder (SAD), and pioneered the use of light therapy for its treatment.
Seasonal affective disorder (SAD) is a mood disorder subset in which people who have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year, most commonly in winter. Common symptoms include sleeping too much, having little to no energy, and overeating. The condition in the summer can include heightened anxiety.
Light therapy—or phototherapy, classically referred to as heliotherapy—consists of exposure to daylight or to specific wavelengths of light using polychromatic polarised light, lasers, light-emitting diodes, fluorescent lamps, dichroic lamps or very bright, full-spectrum light. The light is administered for a prescribed amount of time and, in some cases, at a specific time of day.
Wehr and colleague Anna Wirz-Justice were awarded the Anna-Monika Prize for their work in the chronobiology of depressive illness. The duo carried out the first sleep phase advance experiment in a bipolar patient.
Chronobiology is a field of biology that examines periodic (cyclic) phenomena in living organisms and their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobiology comes from the ancient Greek χρόνος, and biology, which pertains to the study, or science, of life. The related terms chronomics and chronome have been used in some cases to describe either the molecular mechanisms involved in chronobiological phenomena or the more quantitative aspects of chronobiology, particularly where comparison of cycles between organisms is required.
Major depressive disorder (MDD), also known simply as depression, is a mental disorder characterized by at least two weeks of low mood that is present across most situations. It is often accompanied by low self-esteem, loss of interest in normally enjoyable activities, low energy, and pain without a clear cause. People may also occasionally have false beliefs or see or hear things that others cannot. Some people have periods of depression separated by years in which they are normal, while others nearly always have symptoms present. Major depressive disorder can negatively affect a person's personal life, work life, or education, as well as sleeping, eating habits, and general health. Between 2–8% of adults with major depression die by suicide, and about 50% of people who die by suicide had depression or another mood disorder.
Bipolar disorder, previously known as manic depression, is a mental disorder that causes periods of depression and periods of abnormally elevated mood. The elevated mood is significant and is known as mania or hypomania, depending on its severity, or whether symptoms of psychosis are present. During mania, an individual behaves or feels abnormally energetic, happy, or irritable. Individuals often make poorly thought out decisions with little regard to the consequences. The need for sleep is usually reduced during manic phases. During periods of depression, there may be crying, a negative outlook on life, and poor eye contact with others. The risk of suicide among those with the illness is high at greater than 6 percent over 20 years, while self-harm occurs in 30–40 percent. Other mental health issues such as anxiety disorders and substance use disorder are commonly associated with bipolar disorder.
Wehr co-authored "Circadian Rhythms in Psychiatry (Psychobiology and Psychopathology)" with Frederick Goodwin; and, in 1993, "How to Beat Jet Lag," with D. A. Oren, W. Reich, and N. Rosenthal.
Jet lag is a physiological condition that results from alterations to the body's circadian rhythms caused by rapid long-distance trans-meridian travel. For example, someone flying from New York to London, i.e. from west to east, feels as if the time were five hours earlier than local time, and someone travelling from London to New York, i.e. from east to west, feels as if the time were five hours later than local time. Jet lag was previously classified as one of the circadian rhythm sleep disorders.
A circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. It can refer to any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria.
Delayed sleep phase disorder (DSPD), more often known as delayed sleep phase syndrome and also as delayed sleep–wake phase disorder, is a chronic dysregulation of a person's circadian rhythm, compared to those of the general population and societal norms. The disorder affects the timing of sleep, peak period of alertness, the core body temperature rhythm, and hormonal and other daily cycles. People with DSPD generally fall asleep some hours after midnight and have difficulty waking up in the morning. People with DSPD probably have a circadian period significantly longer than 24 hours. Depending on the severity, the symptoms can be managed to a greater or lesser degree, but no cure is known, and research suggests a genetic origin for the disorder.
Advanced Sleep Phase Disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder, is a condition that is characterized by a recurrent pattern of early evening sleepiness and early morning awakening. This sleep phase advancement can interfere with daily social and work schedules, and result in shortened sleep duration and excessive daytime sleepiness. The timing of sleep and melatonin levels are regulated by the body's central circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus.
Biphasic sleep is the practice of sleeping during two periods over 24 hours, while polyphasic sleep refers to sleeping multiple times – usually more than two. Each of these is in contrast to monophasic sleep, which is one period of sleep over 24 hours. Segmented sleep and divided sleep may refer to polyphasic or biphasic sleep, but may also refer to interrupted sleep, where the sleep has one or several shorter periods of wakefulness. A common form of biphasic or polyphasic sleep includes a nap, which is a short period of sleep, typically taken between the hours of 9 am and 9 pm as an adjunct to the usual nocturnal sleep period.
Non-24-hour sleep–wake disorder is one of several chronic circadian rhythm sleep disorders (CRSDs). It is defined as a "chronic steady pattern comprising [...] daily delays in sleep onset and wake times in an individual living in society". Symptoms result when the non-entrained (free-running) endogenous circadian rhythm drifts out of alignment with the light/dark cycle in nature. Although this sleep disorder is more common in blind people, affecting up to 70% of the totally blind, it can also affect sighted people. Non-24 may also be comorbid with bipolar disorder, depression, and traumatic brain injury. The American Academy of Sleep Medicine (AASM) provides guidelines since 2007 with the latest update released in 2015.
A phase response curve (PRC) illustrates the transient change in the cycle period of an oscillation induced by a perturbation as a function of the phase at which it is received. PRCs are used in various fields; examples of biological oscillations are the heartbeat, circadian rhythms, and the regular, repetitive firing observed in some neurons in the absence of noise.
A zeitgeber is any external or environmental cue that entrains or synchronizes an organism's biological rhythms to the Earth's 24-hour light/dark cycle and 12-month cycle.
Alfred J. Lewy, a.k.a. "Sandy Lewy", graduated from University of Chicago, in 1973 after studying Psychiatry, Pharmacology and Ophthalmology. He is a full professor and Vice-Chair of the department of Psychiatry at OHSU, Oregon Health & Science University, and holds an MD and PhD. Prior to moving to Oregon in 1981, Lewy was at the National Institute of Mental Health (NIMH) in Bethesda, Maryland, working with senior colleague Thomas Wehr. In Oregon he has worked closely with Robert L. Sack. As of December 2005, he had 94 publications available on Pubmed.
Circadian rhythm sleep disorders (CRSD) are a family of sleep disorders which affect the timing of sleep. CRSDs arise from a persistent pattern of sleep/wake disturbances that can be caused either by dysfunction in one's biological clock system, or by misalignment between one's endogenous oscillator and externally imposed cues. As a result of this mismatch, those affected by circadian rhythm sleep disorders have a tendency to fall asleep at unconventional time points in the day. These occurrences often lead to recurring instances of disturbed rest, where individuals affected by the disorder are unable to go to sleep and awaken at "normal" times for work, school, and other social obligations.
Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia and excessive sleepiness affecting people whose work hours overlap with the typical sleep period. There are numerous shift work schedules, and they may be permanent, intermittent, or rotating; consequently, the manifestations of SWSD are quite variable.
Light effects on circadian rhythm are the effects that light has on circadian rhythm.
Irregular sleep–wake rhythm is a rare form of circadian rhythm sleep disorder. It is characterized by numerous naps throughout the 24-hour period, no main nighttime sleep episode and irregularity from day to day. Sufferers have no pattern of when they are awake or asleep, may have poor quality sleep, and often may be very sleepy while they are awake. The total time asleep per 24 hours is normal for the person's age. The disorder is serious—an invisible disability. It can create social, familial, and work problems, making it hard for a person to maintain relationships and responsibilities, and may make a person home-bound and isolated.
Sleep inversion or sleep-wake inversion is a reversal of sleeping tendencies. Individuals experiencing sleep-wake inversion exchange diurnal habits for nocturnal habits, meaning they are active at night and sleep during the day. Sleep-wake inversion, when involuntary, can be a sign of a serious disorder.
Robert Leroy Sack is an American physician and researcher specializing in sleep medicine. He is certified by the American Board of Psychiatry and Neurology and the American Board of Sleep Disorders Medicine. On the faculty of the Oregon Health & Science University since 1977, he is the medical director of its Clinical Sleep Disorders Medicine Program which he developed parallel with his research on circadian rhythms.
Charles A. Czeisler is an American physician and sleep researcher. He is a researcher and author in the fields of both circadian rhythms and sleep medicine.
A chronobiotic is an agent that can cause phase adjustment of the body clock. That is, it is a substance capable of therapeutically entraining or re-entraining long-term desynchronized or short-term dissociated circadian rhythms in mammals, or prophylactically preventing their disruption following an environmental insult such as is caused by rapid travel across several time zones. The most widely recognized chronobiotic is the hormone melatonin, secreted at night in both diurnal and nocturnal species.
Michael Terman is an American psychologist best known for his work in applying the biological principles of the circadian timing system to psychiatric treatments for depression and sleep disorders. This subspecialty is known as Chronotherapeutics.