'Sleep and Mental Health' first appeared in Mental Health Today in April 2011. To subscribe to the magazine click here.

Sleep and mental health are interlinked, and treating problems with one can help the other, but this link is still under-recognised.

Dr Dan Robotham, senior researcher at the Mental Health Foundation

Sleep is essential to human life. On average, we spend a third of our life asleep. Sleep regenerates our brains and bodies, and without it we cannot function effectively. During sleep the body undergoes several physiological and psychological processes; processing information, learning and consolidating memories. Not getting enough sleep leads to the build-up of a sleep debt, only repayable through sleeping.

Keeping a regular sleep pattern is important. This relates to the regularity and timing of our sleep. Sleeping at set times each day enables the body to establish a routine, increasing the need for sleep at that time each day. This is based on a mechanism called our internal circadian rhythm.

Furthermore, the type of sleep we get is important. Broadly, the sleep phases include light sleep, deep sleep and rapid eye movement (REM) sleep. Light sleep is the bridge between being asleep and being awake, and the sleeper is easily woken during this phase. Deep sleep is thought to be the most refreshing type of sleep, and it is here that the sleeper is most difficult to waken. REM sleep is a relatively shallow stage in which we experience dreams. REM sleep is thus named because the sleeper moves their eyes whilst in this phase, as if following the images of a dream.


Mental health and sleep

Mental health and sleep are interlinked. Insomnia is the most commonly reported mental health complaint in the UK (Singleton et al, 2001). Mental health problems can affect the amount of sleep, the type, and the time spent in various sleep phases.

People who suffer from depression may experience sleep disturbances which disrupt the process of falling and staying asleep. The sleeper may wake intermittently throughout, or wake early in the morning and be unable to sleep again (Holsboer-Trachsler & Seifritz, 2000).

Roughly 15-40% of people with depression oversleep (Quitkin, 2002), which is possibly worsened by some antidepressants acting as sedatives. Sleep-related disorders such as periodic limb movement disorder and restless legs syndrome can arise as side effects of antidepressants (Picchietti & Winkelman, 2005). People with depression also spend more time in REM sleep and have more frequent rapid eye movements (Lauer et al, 1991). Many antidepressants aim to limit REM sleep (Dunleavy et al, 1972).

People who suffer from bipolar disorder may experience disrupted circadian rhythms, which affects sleep patterns and may lead to sleeping at irregular times throughout the day. Furthermore, changes in circadian rhythms may trigger bipolar disorder (Kupfer et al, 1988).

Insomnia can be a common complaint in people who suffer from schizophrenia (American Psychological Association, 1994); people with schizophrenia may reach deep sleep and REM sleep later (Monti & Monti, 2005), and some such medications affect the ability to maintain sleep.

Anxiety is perhaps the most obvious example of how mental health can affect sleep. Many of us have experienced sleepless nights due to worrying about upcoming events. People with anxiety experience such feelings often, and to the extent where they can severely affect a person's daily life. People who suffer from anxiety tend to spend less time in deep sleep (Monti & Monti 2000).

Anxiety is also an underlying cause of teeth grinding during the night; roughly 70% of people who ground their teeth attributed it to stress and anxiety (Manfredini et al, 2005). Anxiety may also contribute to recurrent nightmares. For example, people who suffer from post-traumatic stress disorder, a type of anxiety, may have disturbed REM sleep and can experience distressing dreams or nightmares as a consequence of past traumas (Habukawa et al, 2007).


Sleep and mental health

Good sleep is fundamental to good mental health, just as good mental health is fundamental to good sleep. Symptoms of poor sleep include fatigue, sleepiness during daytime, poor concentration, irritability and memory loss.

Poor sleep can make people less receptive to positive emotions (Woodson, 2006) in turn making them feel down during the day. A history of insomnia has been shown to increase the risk of developing depression (Cole & Dendukuri, 2003; Riemann & Vodelholzer, 2003).

Mental state is paramount in allowing or preventing insomnia developing into a chronic problem. Anxiety about sleeplessness can make sleeping more difficult. Anyone who has 'watched the clock' throughout the night will recognise this. The clock is used as a gauge to monitor sleep performance. The pressure to achieve sleep turns into a type of 'performance anxiety', which in turn makes it more difficult to sleep. Such thoughts perpetuate a negative cycle over time.

This is why therapies that aim to challenge negative thoughts about sleeping and re-establish good sleep patterns are most effective for
treating chronic insomnia. There is comprehensive evidence to suggest that cognitive behavioural therapy (CBT) is effective in this context. Across 85 clinical trials (and 4,194 participants), it was associated with improvement in 70% of cases (Morin et al, 2006; 1999).

A comprehensive CBT approach for insomnia includes a sleep hygiene regime, relaxation training, attention to sleep patterns, and attention to thoughts and behaviours that hinder sleeping (Perlis et al, 2011). Full CBT courses delivered by trained sleep practitioners can be intensive. Still, as few as four CBT sessions may be effective for less complex cases of insomnia (Edinger et al, 2007). Simple CBT-based interventions such as information booklets and internet courses may help if the insomnia has not become too severe or long-lasting.

Sleep hygiene refers to lifestyle and environmental factors that can affect sleep. Substances like caffeine, nicotine and alcohol have an effect. The environment of our bed and bedroom can help or hinder sleep; noise, light, temperature, ventilation. Positive sleep hygiene may help to improve sleep quality, but will not treat chronic insomnia.

Relaxation is also an important element of CBT. The art of relaxing may require patience, discipline and practice. People with insomnia often find it difficult to relax before and during bedtime. Relaxation training involves paying attention to breathing and muscle tension. People who have trouble sleeping should aim to 'wind down' with relaxing activities at least an hour before going to bed.

Someone who wishes to overcome insomnia must break the link between their negative thoughts about bedtime, and how they feel about these thoughts. CBT aims to question the assumptions behind our thoughts, reconfiguring links between thoughts and emotions. For example, even people with insomnia get some sleep on most nights, but tend to underestimate the amount of sleep they have had. Thinking about sleep in a negative way increases anxiety about not sleeping, and subsequent emotional consequences feedback into thoughts, making sleep ever more difficult.

CBT approaches encourage not pressurising oneself to 'achieve' sleep, instead taking practical steps to help adjust to the process. The absence of effort allows good sleepers to sleep easily. They treat sleep as an automatic process that happens when they go to bed. In other words, they do not spend time thinking about sleep, or about the need to sleep.

On the other hand, people with insomnia often place undue pressure on themselves to sleep. To this end, CBT uses a technique called paradoxical intention. Someone who is finding it difficult to sleep would be advised to remain awake passively, reducing the effort spent forcing sleep yet maintaining the commitment to get to sleep.

In order to sleep, the bed and bedroom need to be psychologically associated with sleeping, not with sleepless nights. Lying in bed awake, thinking or worrying, is never conducive to sleeping.

In these circumstances CBT recommends getting up, leaving the room and engaging in a relaxing activity elsewhere, returning to bed when sleepy. Spending significant time in bed without falling asleep strengthens the association between the bedroom and sleeplessness, making the act of getting to sleep more difficult. Getting out of bed may seem counterproductive, but in the long-term it allows reestablishment of the psychological connection between sleeping and the bedroom environment.

Creating a healthy, regular sleep pattern is perhaps the most challenging aspect of CBT for insomnia. People with insomnia often have inappropriate sleep patterns. Keeping a sleep diary will help gauge the amount of time spent sleeping per night. Following this, a person needs to set a bedtime and waking time based on the average amount of time they spend asleep each night. For example, someone who gets an average of five and a half hours sleep per night may want to set their alarm for time 7:00am and go to bed at 1:00am. This leaves a six-hour period in the day in which the person can sleep. This sleep window can be increased gradually if the person begins to sleep sufficiently into this pre-determined time.



Sleep is a complex process that is crucial to good mental and physical health. It is important to recognise the link between sleep and mental health; people who visit sleep disorder clinics complaining of insomnia may have underlying mental health problems. In such cases, the mental health problem needs to be treated alongside the insomnia.

Sleeping poorly increases the risk of poor mental health. The importance and benefits of sleep for mental and physical health should be highlighted in national and local public health campaigns, including schools and workplaces. There is a dire need for people to begin to take sleep seriously as a health concern.


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