By Dr. Lillian Mezey
What if there were something that could make you smarter, improve your memory, enhance your creativity, help you perform better, improve your mood, help prevent weight gain, protect against dementia, boost your energy and concentration, and promote a longer life? And what if this thing were free, natural, and without side-effects? Would you sign up? Would you want to provide it for your children?
Sleep can do all that and more, yet despite strong evidence of its benefits, we are getting less of it. With industrialization has come electric lights allowing us to stay up later, television (and now internet and smart phones), inflexible work and school schedules (and early start times), shift work, and seemingly round-the-clock work pressure.
Sleep is complicated and still much of a mystery, even to sleep researchers. Over the course of a full night of sleep, our brain goes through different “stages” of sleep in repeated cycles of approximately 90 minutes each. First, we enter REM (rapid eye movement) sleep and then fall into deeper levels of non-REM sleep. Each sleep stage serves a different function, all important in different ways.
Our culture seems to romanticize “short sleepers” (those who sleep fewer than 6 hours a night) as being more industrious, tougher, more successful. Except for a small percentage with a rare genetic mutation, the majority of those sleeping fewer than six hours a night on a regular basis are sleep-deprived and are probably functioning at a lower level than they would be otherwise.
In addition to helping us feel better and function better, getting enough sleep can literally be a life-saver. There is strong evidence, some new and surprising in its scope, describing the multitude of serious health risks associated with sleep deprivation. These include obesity, heart disease, stroke, diabetes, cancer, dementia, car accidents, depression and anxiety, and shorter life span. Adequate sleep, and a regular sleep schedule, acts as a natural mood stabilizer in bipolar disorder. It also strengthens our emotional resilience and ability to cope with stress (which we know, but tend to lose sight of!).
Our sleep schedule is determined by several different factors. Understanding these can help us regulate our own. We have an internal biological sleep clock of just over 24 hours. This is further influenced by light and dark cues; darkness triggers the release of melatonin (the “vampire hormone”) in our brains, which signals to our brain and body that it’s time to sleep. Light cuts off melatonin release. This is why exposure to light in the evenings/night, especially the blue light of computer screens and cell phones, disrupts our sleep cycle. Another factor is a chemical called adenosine, which builds up in our system over the hours we are awake and causes “sleep pressure,” a strong urge to sleep. We all know what this feels like, when we just can’t keep our eyes open any longer. Caffeine blunts the effects of adenosine, which is why it can cause insomnia. Adenosine continues to build up in your system, however, even when you are under the influence of caffeine, leading to that familiar post-caffeine “crash.”
Genetically, some people seem to be hard-wired as “early birds” or “night owls.” The remaining (thought to be about 80%) are somewhere in between. We all know how difficult it is to try to change our natural sleep cycles. I wish I could run regularly before work with my 5:30 a.m. running friends, but I’m just not wired for that. Generally, we feel best if we plan our sleep schedules around our own personal natural rhythms.
Our sleep needs, timing, and architecture change over the course of our live span, starting even before birth. As is obvious to any parent of teenagers, the sleep cycle of adolescents is naturally later; their circadian rhythm is shifted such that they don’t feel tired until later at night and their natural wake-up time is later in the morning. (No, they are not just lazy). In addition, adolescence is a time of rich, deep NREM sleep, vital for the intense processes of brain maturation occurring during those years. Deep NREM sleep seems to be crucial for “neuronal pruning” in adolescence, when brain circuitry is refined and strengthened, leading to improvements in such cognitive domains as critical thinking and reasoning. For these reasons, early school start times in middle and high school can be harmful to our children’s development and functioning; some school systems have recognized this and made changes to their schedule.
One striking benefit of sleep is its powerful effects on memory and learning. During sleep, information is transferred from short-term storage (in the hippocampus) to longer term memory, clearing the way to learn new information. Therefore, if we have slept the night before, we will retain significantly more of what we learn the next day. In addition, getting sleep after learning allows for memory consolidation. During the night of sleep, the new information is transferred to long term and more secure storage. Pulling an all-nighter to study for a test actually accelerates forgetting; we are much better off studying as much as we can and then going to bed at a decent hour before an exam.
Insomnia is common, and the good news is that there is much we can do to address it. Before considering the pros and cons of sleep meds (and there are plenty of cons), the best first step is good “sleep hygiene.” Key elements include: keeping to a regular daily sleep schedule (including weekends), limiting caffeine and alcohol use, regular exercise (but not too late in the day), limiting screen time in the evenings, morning sunlight exposure, limiting naps, avoiding heavy foods before bedtime, a relaxing bedtime routine, and sleeping in a cold, dark and quiet room. A hot bath or shower before bed can help, because it actually cools your body down afterwards.
If sleep hygiene doesn’t fully do the trick, a kind of psychotherapy called CBT-I (cognitive behavioral therapy for insomnia) is the first-line treatment recommendation. This is a structured, short-term course of psychotherapy focused on changing thoughts and behaviors to promote sleep. It is much safer than sleeping medication, has longer lasting efficacy, and is actually significantly more effective. One challenge can be difficulty finding a CBT-I therapist. Online CBT-I options now exist and include: SHUTi, Sleepio, RESTORE, and CBT-I. All are effective, but as expected, drop-out rates are higher for online therapy vs. in-person treatment.
Sleeping medications may have a role for short-term use in acute insomnia, but they often make sleep problems worse in the long run, can be addictive, and can lead to tolerance and withdrawal insomnia. Also, they have many possible side-effects, including daytime sedation and cognitive impairment (including new data on impairment of next morning driving), dizziness, falls, and depression. Ambien has been associated with strange and dangerous sleep behaviors, such as sleep walking and even sleep driving while impaired.
So, start with the basics. Make time to sleep and take some time to relax before bedtime. Your brain, body, and family will thank you.