Understanding Insomnia: Why You're Not Feeling Sleepy

There are many reasons why you might not feel sleepy. Insomnia, a sleep disorder that affects around 10% of the world's population, can be caused by stress, jet lag, a health condition, medication, or even the amount of coffee you drink. Other sleep disorders include sleep apnea, restless leg syndrome, and narcolepsy. Lifestyle habits, such as excessive caffeine consumption or screen time before bed, can also interfere with sleep. Additionally, certain medications, physical or mental health conditions, and chronic pain can contribute to sleep difficulties. Sleep reactivity, or how stress affects sleep, varies from person to person, with some experiencing greater sleep disturbances during stressful periods.

Caffeine, alcohol, and heavy meals can disrupt sleep

Caffeine, alcohol, and heavy meals can all negatively impact your sleep. Caffeine, a stimulant, promotes wakefulness by blocking adenosine, a sleep-inducing chemical. It can make you fall asleep later and reduce the amount of deep, slow-wave sleep you get, which is critical for feeling refreshed the next day. The effects of caffeine can last up to five hours or longer, depending on various factors, including the dose, frequency of consumption, and your genetic makeup. To ensure better sleep quality, it is recommended to avoid caffeine at least eight hours before bedtime.

Alcohol, on the other hand, can lead to frequent wakings and overall low-quality sleep. It can alter your sleep architecture, causing more deep sleep initially and less REM sleep. Later in the night, once the body has metabolized the alcohol, you may experience more frequent wakings and fragmented sleep. Alcohol can also worsen snoring and sleep apnea, and interfere with circadian rhythms, increasing the likelihood of pauses in breathing during sleep. Experts recommend avoiding alcohol at least three hours before bed.

Heavy meals close to bedtime can leave you uncomfortably full and contribute to obesity, a risk factor for sleep apnea. Spicy foods can cause painful heartburn, disrupting your sleep. It is advisable to eat dinner at least a couple of hours before bedtime and keep the meal light to promote better sleep.

Jet lag and shift work can cause insomnia

Jet lag and shift work can both cause insomnia. Jet lag is a type of fatigue caused by travelling across different time zones. The body is synchronised to night and day by the action of sunlight through brain chemicals or neurotransmitters, especially melatonin. Travelling to a different time zone disrupts the body's 24-hour circadian rhythm, resulting in insomnia, fatigue, irritability, and impaired concentration. The body needs anywhere from a few days to a few weeks to acclimatise to the new time zone.

Shift work disorder is a condition that affects people who work outside the hours of 6 am to 7 pm, including fixed and rotating shifts. It is a circadian rhythm sleep disorder characterised by a misalignment between the body and the circadian rhythms that regulate the sleep-wake cycle. Shift work disorder causes insomnia when workers attempt to sleep and excessive sleepiness while they are at work. The average person with shift work disorder loses one to four hours of sleep per night.

Shift-workers commonly suffer from insomnia. Individuals working in rotating shifts for more than 15 days have a significantly higher prevalence of insomnia than day workers. Rotating shift workers experience more daytime sleepiness than day workers, and the duration and quality of their sleep and sense of well-being are lower.

Chronic pain and mental health disorders are linked to insomnia

Insomnia is a common sleep disorder that can be caused by or associated with chronic pain and mental health disorders. Insomnia is characterised by difficulty falling or staying asleep, or waking up too early in the morning. It is rarely an isolated condition and is often a symptom of another illness.

Chronic Pain and Insomnia

Pain and sleep have a bidirectional relationship. Sleep deprivation can decrease pain thresholds and increase sensitivity to painful stimulation, while pain can disrupt sleep. This creates a vicious cycle where a bad night's sleep enhances pain, which in turn disturbs sleep, and the cycle continues and amplifies over time.

Chronic pain patients with insomnia tend to report more severe pain, longer pain duration, and greater levels of anxiety, depression, and health anxiety than those without insomnia. Sleep disturbances in chronic pain patients can manifest as longer sleep onset, more frequent and longer awakenings after sleep onset, shorter total sleep time, lower sleep efficiency, and poorer sleep quality.

Mental Health Disorders and Insomnia

Mental health disorders such as depression, anxiety, bipolar disorder, schizophrenia, and post-traumatic stress disorder (PTSD) are highly associated with insomnia and other sleep disorders. For example, people with insomnia are twice as likely to develop depression, and early morning wakefulness can be a sign of depression. Sleep disturbances are present in up to 80% of people with schizophrenia and 80-90% of people with bipolar disorder. Additionally, people with sleep disorders are more likely to develop PTSD when placed in stressful situations.

Treatment Options

The first-line treatment for insomnia involves improving sleep hygiene, such as maintaining a regular sleep schedule, avoiding stimulating activities before bed, and creating a comfortable sleep environment. Relaxation techniques like deep breathing and progressive muscle relaxation can also help reduce anxiety about falling asleep.

Pharmacological interventions for insomnia may include antidepressants, melatonin supplements, and herbal remedies like valerian root. Cognitive-behavioural therapy can also help control or eliminate negative thoughts and worries that interfere with sleep.

Screen time and stimulating activities before bed hinder sleep

Screen time and stimulating activities before bed can significantly impact your sleep quality and duration. The bright lights and constant stimulation from electronic devices can disrupt your sleep by tricking your brain into thinking it's time to wake up. This is especially true for blue light emitted by digital screens, which can suppress melatonin production and disrupt your circadian rhythm.

The effects of screen time on sleep are well-documented. The bright light from screens can suppress the production of melatonin, a hormone that plays a crucial role in regulating sleep-wake cycles. By disrupting the release of melatonin, screen time before bed can interfere with your body's natural sleep-wake cycle, making it difficult to fall and stay asleep.

In addition to the bright lights, the stimulating content on screens can also keep your brain active and engaged, making it harder to wind down and prepare for sleep. Activities such as texting, playing video games, or even watching exciting shows or movies can stimulate your brain and kick your body into wake-up mode. This stimulation can lead to increased alertness and make it challenging to relax and fall asleep.

To improve your sleep, it is recommended to avoid screen time right before bed. Instead, opt for relaxing activities that don't involve screens, such as reading a book, listening to soothing music, or practising yoga. Establishing a wind-down routine that doesn't involve screens can help signal to your body that it's time to prepare for sleep.

Additionally, it's important to manage your daytime habits. Sticking to a consistent sleep schedule, getting regular exercise, and limiting caffeine, alcohol, and nicotine intake can all contribute to better sleep quality. By making these adjustments and creating a soothing bedtime routine, you can improve your sleep and overall well-being.

Sleep reactivity: stress can cause insomnia

Sleep reactivity is a measure of how much stress affects your sleep. Individuals with highly reactive sleep systems experience drastic deterioration of sleep when stressed, whereas those with low sleep reactivity proceed largely unperturbed.

Research has shown that genetics, family history of insomnia, gender, and environmental stress influence how the sleep system responds to stress. Sleep reactivity is most clinically pertinent when in excess, as high sleep reactivity predicts the risk of future insomnia disorder.

The Ford Insomnia Response to Stress Test (FIRST) is a self-report instrument designed to assess sleep reactivity. The test asks individuals to rate the likelihood of experiencing difficulty sleeping in response to a number of both broad and highly specific hypothetical stressors.

Sleep reactivity is a predisposition to sleep disturbance during environmental changes, pharmacological challenges, or stressful life events. As such, individuals with highly reactive sleep systems are prone to insomnia disorder after a stressor, which can impede recovery from traumatic stress and increase the risk of psychopathology.

The FIRST can be used to identify individuals at risk of insomnia a priori, allowing early interventions to prevent insomnia and promote resilience to adversity.

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