This is like the classic question, “Which came first, the chicken or the egg?” When talking to patients about their medical history, a lot of information can be gained by trying to unravel the “chicken or egg” conundrum. If someone is asked, “When was the last time you felt well?” he almost always knows the month and year. The follow-up question, “What happened in your life during the previous few months?” can shed a lot of light on the problem. Some people experienced an emotional trauma that has not resolved, leading to anxiety, depression, or difficulty sleeping. Subsequently, they develop physical ailments such as headaches, digestive issues, or chronic pain. Other people suffered a physical trauma that disrupted their sleep and led to anxiety and depression. The physical trauma could have been an accident or an illness, a surgery, or a lifelong disability.
Any initiating trauma, whether physical or emotional, can lead to disrupted sleep. This can be due to the physiological changes brought about by a medical condition or by the worry and stress caused by a change the initiating trauma has brought about in relationships or socioeconomic factors. For example, if someone is in a car accident and is injured, she may suffer both physical and emotional trauma. The physical injury may cause pain, disfigurement, or disability. This may result in an inability to work, either inside or outside the home. People injured in this way may be unable to care for their children, parents, or partner. Perhaps now they cannot financially support their family. This can lead to worry, anxiety, and depression. Individuals who are unable to fulfill their usual responsibilities commonly feel ill at ease in their relationships and society at large. These physical and emotional stressors can adversely impact a person’s sleep. Not only can pain from a physical injury disrupt the normal sleep cycle, but the emotional strain of altered circumstances can lead to insomnia. Head injuries, in particular, can disturb a person’s normal brain function and sleeping pattern. The physical and emotional trauma caused by traumatic brain injury (TBI) can take years to resolve.
The example of a car accident is a common one and can be broadened. Any serious illness or life change can lead to emotional problems and sleep disorders. Some people are able to bounce back from these situations and get right back on course. Others, due to the severity of their injury or illness, never truly recover and may carry the secondary burden of poor sleep and emotional distress for the rest of their lives. Yet again, some people are genetically predisposed to suffer from emotional or sleep disturbances. Such conditions are known to run in families. With increasingly sophisticated tests such as gene sequencing, functional magnetic resonance imaging of the brain (fMRI), and a greater understanding of how brain cells actually work, scientists are able to pinpoint the reason some people are affected with these disorders and others are not. For instance, generalized anxiety disorder carries a moderate genetic risk with a 30 percent risk of inheritance. (“Genetics of Generalized Anxiety Disorder and Related Traits” Dialogues in Clinical Neuroscience 2017 by Michael Gottschalk and Katharina Domscke)
A 2018 meta-analysis found 44 genes that may predispose an individual toward major depression. (Nature Genetics 2018 by Naomi Wray, Stephan Ripke and the Major Depressive Disorder Working Group) Continued research into sleep reveals that it is under genetic control. There are many layers of biochemical processes involved in sleep, and genetic abnormalities can account for various types of sleep disorders. (Cell 2011 “Genetics of Sleep and Sleep Disorders,” by Amita Seghal and Emmanuel Mignot)
It is important to note, however, that the authors of these studies, and many more, point out that anxiety, depression, and sleep problems are significantly influenced by environmental, societal, and lifestyle factors. This means that just because a person’s genetics make them susceptible to these conditions, they may not actually experience any symptoms of these illnesses. In Western medicine we call this “gene expression.” Whether certain genes are expressed depends upon where, how, and with whom a person lives. If you live in a crowded, polluted area, if you suffer from loneliness and isolation, and if you eat poorly and rarely exercise, the genetic information stored in the cells of your body can be translated in such a way as to allow some diseases to occur.
Even if you have been fortunate and have avoided a major crisis, like an accident or illness, the way you live your life day to day makes a significant difference to your health. One of the main contributors to good health is adequate restful sleep. Humans have always realized that sleep is important, but we are just starting to understand exactly why. We all know that when we sleep well, we wake up refreshed and energized. Our thinking is clear and our memory is sharp. We also know that the reverse is true. When we are sleep-deprived, we feel sluggish, our reaction times are slower, and we have difficulty with problem-solving. In fact, one British study that compared sleep-deprivation to alcohol consumption found that 17–19 hours without sleep resulted in the same level of performance on speed and accuracy testing as having a blood alcohol level of 0.05 percent. After 23 hours, the performance levels were the same as if a person had a blood alcohol level of 0.1 percent, which is well past being legally intoxicated. (Occupational and Environmental Medicine (2000), by A. Williamson and A. Feyer)
So why is sleep so important to the brain? What happens to our brain when we sleep? It gets cleaned. In the body, the system that removes the waste products of cellular metabolism is the lymphatic system. A fluid called lymph picks up these by-products and takes them through lymph vessels to the nodes and organs, such as the spleen, to be processed. But, the brain does not have lymph vessels or nodes like the rest of the body. The equivalent of lymph in the brain is known as cerebrospinal fluid (CSF). The CSF carries the waste products of the brain cells, and it was recently discovered that the way the CSF travels between cells deep in the brain is through spaces between the wall of the blood vessels and the projections of a type of brain glial cell called astrocytes. Glial cells are not neurons. The various types of glial cells support the function of the neurons that make up your brain. So, instead of a totally separate system of vessels to transport waste products as is found in the lymphatic system of the body, the brain uses the space between the outside of the blood vessel and the specialized glial cells to clear the brain of toxic by-products. Scientists have named these channels the glymphatic system, meshing the words “glial” and “lymphatic” to convey its function and form.
This is all very interesting, but you may be thinking, “What does this have to do with sleep?” It turns out that the glymphatic system is incredibly active when we are asleep and is almost completely suppressed when we are awake. In order for harmful substances to be cleared from the brain, you must be asleep. If these toxic byproducts accumulate in the brain, over time diseases like Alzheimer’s and other forms of dementia may occur. The glymphatic system may also distribute nutrients and neurotransmitters that keep the brain functioning normally. Since the activity of the glymphatic system is enhanced during sleep, it is no wonder that we need adequate amounts to feel alert and well rested on waking.
Even our mood improves after sleeping well. In fact, normal sleeping patterns are linked to normal mental health. For people who have illnesses such as depression, anxiety, bipolar disorder, or schizophrenia, sleep disturbances are common and may actually precede mental illness in susceptible individuals. Fortunately, because sleep and emotional well-being are so closely intertwined, improving sleep quality in such patients can decrease the symptoms of psychiatric illness by as much as 50 percent. (“Why Do We Sleep?” by Russell Foster, TED Talk, June 2013).
Sleep is one of the principal resources you need to keep your body and mind functioning well. Along with nutritious food and a safe and supportive living environment, sleep is essential to maintain your equilibrium in life. Another word for this equilibrium is “homeostasis,” your ability to sustain all the physiological processes your body needs to stay healthy and in balance.
The above is an excerpt from True Wellness The Mind: How to Combine the Best of Western and Eastern Medicine for Optimal Health by Catherine Kurosu, MD, LAc and Aihan Kuhn, CMD, OBT, Pub date July 2019, YMAA Publication Center, ISBN: 978-1-59439-664-9.