Emotional Hibernation: Sleep's Escape From Feeling

Sleep is a period during which the brain engages in various activities necessary for life and closely linked to one's quality of life. While previously believed to be a passive activity, sleep is now understood as a dynamic state where the brain cycles through different stages of sleep, including REM (rapid-eye movement) sleep and non-REM sleep. These sleep stages play a crucial role in learning, memory, and restoration.

However, achieving restful sleep can be challenging for many individuals. Factors such as lifestyle habits, medications, physical or mental health conditions, and stress can interfere with one's ability to fall asleep or maintain restful sleep throughout the night. Understanding and addressing these factors are essential for promoting healthy sleep and overall well-being.

The science of sleep

Sleep accounts for a significant portion of our lives, yet many of us don't get enough of it. Sleep is vital for our health and well-being, and when we don't get enough, our health risks increase.

Throughout your sleep, your brain will alternate between two main types of sleep: REM (rapid-eye movement) sleep and non-REM sleep. Non-REM sleep is further divided into four stages. The first stage is the transition between wakefulness and sleep. The second stage is light sleep, where heart rate and breathing regulate, and body temperature drops. The third and fourth stages are deep sleep, which is the most restorative and crucial for learning and memory. As you enter REM sleep, your eyes move rapidly behind closed lids, and your breath rate increases. Your body becomes temporarily paralyzed as you dream.

The cycle repeats itself, but with each repetition, you spend less time in the deeper stages of sleep and more time in REM sleep. This cycle typically occurs four to five times throughout a night of healthy sleep.

The quality and duration of sleep are influenced by various factors, including lifestyle habits, medications, physical health, and mental health. For instance, consuming caffeine or alcohol close to bedtime can disrupt sleep. Chronic pain, stress, and mental health disorders such as anxiety and depression are also associated with sleep problems.

Additionally, our sleep is regulated by two main processes: circadian rhythms and sleep drive. Circadian rhythms are controlled by a biological clock in the brain, which responds to light cues by producing the sleep hormone melatonin at night and switching it off during the day. Sleep drive, on the other hand, is our body's natural craving for sleep, similar to hunger.

Understanding the science of sleep is crucial as it significantly impacts our physical and mental health. Poor sleep can lead to various issues, including increased symptoms of depression, seizures, high blood pressure, migraines, compromised immunity, and even a prediabetic state in healthy individuals.

To improve sleep quality, it is essential to address any underlying issues, such as stress, anxiety, or physical discomfort. Creating a relaxing bedtime routine, limiting screen time before bed, and maintaining a consistent sleep schedule can also promote better sleep.

Sleep and mental health

How Sleep Affects Mental Health

Research has shown that insufficient or poor-quality sleep can increase the risk of mental health disorders. Sleep helps maintain cognitive skills such as attention, learning, and memory, and poor sleep can make it harder to cope with stressors and accurately perceive the world. Sleep is also important for the consolidation of positive emotional content, and a lack of sleep can influence mood and emotional reactivity. Poor sleep has been linked to an increased risk of depression, anxiety, and even suicidal ideation.

How Mental Health Affects Sleep

Living with a mental health problem can affect sleep in several ways. For example, anxiety can cause racing thoughts and worries that keep you awake, and may also trigger panic attacks while trying to sleep. Depression and seasonal affective disorder (SAD) can cause insomnia or make you sleep more than usual. Trauma can cause nightmares or night terrors that disturb your sleep, and you may feel unsafe or uncomfortable in bed or in the dark. Paranoia and psychosis may also make it difficult to sleep, as you may hear or see things that are frightening or disturbing.

Improving Sleep and Mental Health

Given the close relationship between sleep and mental health, improving sleep may be a component of treating many psychiatric disorders. Cognitive behavioral therapy (CBT) and medication are common treatments for insomnia, and cultivating healthy sleep habits can also help improve sleep quality.

Sleep reactivity

Individuals with highly reactive sleep systems experience a drastic deterioration of sleep when stressed. Research has identified several factors that influence how the sleep system responds to stress, including genetics, family history of insomnia, gender, and environmental stress. Sleep reactivity is particularly problematic when it is excessive, as it predicts a higher risk for future insomnia disorder and severe insomnia phenotypes, such as sleep onset insomnia and short sleep insomnia.

Additionally, high sleep reactivity is linked to an increased risk of shift-work disorder, depression, and anxiety. Stress-related worry and rumination can further exacerbate sensitive sleep systems, making it harder to fall and stay asleep.

The impact of sleep reactivity can be significant, as disrupted sleep just a few nights per week has been linked to an increased risk for depression. This can create a cycle where the frustration caused by sleep difficulties further exacerbates the issue.

To address sleep reactivity, it is important to establish good sleep habits and a consistent sleep routine. This includes limiting daytime naps, powering down electronic devices before bed, scheduling worry time during the day, maintaining a regular sleep schedule, and customizing one's sleep environment to minimize distractions and ensure comfort.

By addressing sleep reactivity and prioritizing good quality sleep, individuals can improve their overall health and well-being, as sleep plays a crucial role in supporting physiological, psychological, and behavioral functions.

Sleep and chronic pain

Sleep is a period during which the brain is engaged in a number of activities necessary to life. It accounts for one-quarter to one-third of the human lifespan. Sleep is vital to the rest of the body and when people don't get enough sleep, their health risks rise.

Chronic pain is highly comorbid with sleep that is deficient in duration or quality. The pain-sleep relationship is a bidirectional one: pain can disrupt sleep, and short or disturbed sleep in turn lowers pain thresholds and increases spontaneous pain.

The Link Between Sleep and Pain

There is a robust evidence base for the link between sleep and pain. Experimental, cohort, and longitudinal studies have all demonstrated that restricted sleep is linked to greater pain. Experimental studies have shown that sleep deprivation in healthy subjects, in particular slow-wave sleep restriction (deep restorative sleep), is associated with increased pain stimulus responses. Prospective longitudinal studies focusing on the effect of sleep on future pain have reported similar findings.

The Temporal Relationship Between Sleep and Pain

The bidirectionality of the relationship is widely accepted, with poor sleep leading to worse pain and pain negatively impacting sleep. There is a growing body of evidence that suggests a temporal precedence for sleep over pain, such that sleep impairment is a stronger predictor of pain than pain is a predictor of sleep impairment.

Sleep Problems as a Risk Factor for Chronic Pain

Sleep problems have been identified as a risk factor for the development of chronic pain. A Swedish prospective population study identified that problems with initiating sleep, maintaining sleep, early awakening, and non-restorative sleep predicted the onset of chronic widespread pain over 5 and 18 years in individuals with no pain at baseline, irrespective of mental health status. In addition, sleep problems and fatigue independently predicted chronic widespread pain at 5 years.

Nociceptive and Neuropathic Pain

Nociceptive pain is caused by damage to body tissue and is commonly treated with traditional analgesics and anti-inflammatory medication. Neuropathic pain is associated with changes to the nerves themselves and affects the way pain signals are sent back to the brain. Nociplastic pain is a new category of pain experience introduced by the International Association for the Study of Pain (IASP) in 2017. Nociplastic pain is defined as "pain arising from the altered function of pain-related sensory pathways in the periphery or central nervous system, causing increased sensitivity."

Interventions to Improve Sleep for People with Pain

Interventions to improve sleep for people with pain include pharmacological and a range of other approaches. Although pharmacotherapy treatments may offer short-term solutions to problems such as sleep latency (taking a long time to fall asleep), they may have unwelcome side effects and are not recommended for long-term use. Behavioral and psychological interventions have gained traction in recent years as ways to improve sleep without side effects and to provide long-term support.

Addressing sleep and providing ways to support and improve sleep can provide benefit to many. A range of sleep problems can be addressed through existing interventional approaches that are underpinned by established theories.

Sleep and shift work

Shift work can be a challenge for many people, and it is not surprising that it can significantly impact one's sleep and overall health and well-being. Working outside the typical 9-to-5 schedule, such as overnight, early mornings, or rotating shifts, disrupts the body's natural 24-hour sleep-wake cycle known as the circadian rhythm. This misalignment between work hours and the natural cues to be awake or asleep can have detrimental effects on shift workers' health and sleep quality.

Health Risks of Shift Work

Shift work has been linked to an increased risk of serious health issues, including metabolic syndrome, accidents, and certain types of cancer. Shift workers are more prone to develop metabolic syndrome, a cluster of conditions that raise the risks for heart disease, diabetes, and stroke. Additionally, disrupting the circadian rhythm through shift work has been associated with a higher risk of colorectal cancer. The exposure to artificial light at night and complex genetic and hormonal interactions are contributing factors to this increased risk.

Furthermore, shift work has also been implicated in a higher prevalence of insomnia and mental disorders compared to non-shift workers. The disturbance of the circadian rhythm can lead to hormonal imbalances, including alterations in melatonin and cortisol levels, which, in turn, contribute to metabolic disorders such as obesity and type 2 diabetes. Shift workers also experience higher white blood cell counts, which can compromise immunity and increase the risk of cardiovascular disease and ischemic stroke.

Strategies for Better Sleep with Shift Work

Now, let's discuss some strategies to improve sleep for those engaged in shift work:

• Timing of Light Exposure: Graveyard shift workers should minimize light exposure after their shift if they intend to sleep right after returning home. Wearing blue light-blocking glasses or using blackout shades in the bedroom can be helpful.
• Prioritize Sleep on Days Off: It is essential to make time for sufficient sleep on days off, even if it means sacrificing some social activities.
• Maintain a Consistent Shift Work Schedule: Minimize the number of consecutive days spent working challenging shifts, and try to stick to a clockwise rotating shift schedule, as it is easier for the body to adjust.
• Talk to Your Employer: Discuss the possibility of reducing the number of overnight shifts or request more flexibility to accommodate your sleep needs.
• Practical Solutions: Find solutions that allow you to get more restful sleep, such as napping before or during shifts (if possible) and creating a supportive work environment.
• Meal Timing and Diet: Maintain regular meal timings, with the last large meal at least three hours before bedtime. Avoid alcohol within three hours of bedtime, and opt for a balanced, low-fat diet with plenty of fruits, vegetables, and cereals.
• Consistency in Sleep Schedule: Night shift workers should maintain the same sleep schedule every day, even on days off, to align their body clock with their sleep pattern.
• Gradual Adjustment: For rotating shift workers, gradually adjust your sleep schedule before transitioning to a new shift. For example, if you are moving from an evening shift to a night shift, delay your bedtime and wake-up time by one to two hours each day for a few days before starting the night shift.
• Light Therapy: Using light therapy or purchasing a light box to expose yourself to intense but safe amounts of light at specific times can help adjust your body's sleep cycle.
• Workplace Conditions: Employers should create a bright and cool work environment for night shift workers to promote alertness and safety.
• Social Support: Educate your family and companions about your unique schedule and sleep needs. Post a shift work calendar, reduce noise and light during your sleep hours, and seek their help with childcare and household tasks.
• Sleep Hygiene: Practice good sleep hygiene, including maintaining a consistent sleep schedule, creating a comfortable sleep environment, and establishing a relaxing bedtime routine.

By implementing these strategies, shift workers can improve their sleep quality and mitigate some of the negative impacts of shift work on their health and well-being.

Frequently asked questions