Dreams mostly occur during the Rapid Eye Movement (REM) phase of sleep. Sleep is divided into two stages — Non-Rapid Eye Movement (NREM) phase and REM phase, which is popularly known as ‘dream sleep.’
The NREM sleep has three stages, in which the stages I and II together can be considered as ‘light sleep’ and stage III is ‘deep sleep.’ The recordings on electroencephalography, while a person is sleeping, show that the waves start to slow down in frequency.
A typical sleep cycle lasts for an hour and a half, and starts with light sleep, delves into a deep sleep and then to dream sleep, meaning, NREM phase is followed by REM phase.
Normally, the first half of sleep will have more ‘deep sleep’ and latter half will have dense REM phase, which is why dreams are common during early morning hours. A person becomes aware of his or her surroundings and understands reality, even when he or she wakes up from a REM sleep. This is because the electrical activity in the brain during the REM sleep is similar to the ones when a person is awake.
Dreams during REM stage can be recollected in detail. Self-report is the only one way to study these dreams.
It is fascinating how dreams appear real at the time. Similar experiences occur in patients with schizophrenia, the difference being, they happen when they are awake.
During REM stage, paralysis of muscles sets in, which means the person will not able to move or speak. It is a safety mechanism of the body that allows us to experience the dream without acting on it. But this paralysis could be lost in a condition increasingly being identified as REM behaviour disorder, where the patient shouts or moves violently during sleep. Since this could be a symptom of neuropsychiatric illness, it is advised to seek a neurologist’s consultation.
Frightening dreams will awake the person from sleep in distress, though this waking episode may not always be remembered. Patients have described dream experiences wherein they faced their own death or death of family members, or being chased by bizarre creatures or snakes. These frightening dream experiences could stop a person from returning to sleep, they would prefer to stay awake lest the nightmare returns.
The person remembers the dream after waking up, without any confusion, but may have fear, sweating, restlessness, palpitations, dry mouth and apprehension of an impending doom.
The person may become preoccupied with fear throughout the following day. Lack of quality sleep can cause irritability and headache and could lead to poor performance at work, academics or relationships. When such scary dreams occur frequently and its impact felt on the daily life of a person, the condition is termed nightmare disorder or dream anxiety disorder, a type of sleep disorder classified under Parasomnias.
Nightmare disorder occurs in up to 5% of people and is usually a treatable condition. The clinician, however, has to rule out possible depressive or anxiety disorders including post-traumatic stress disorder.
Treatment: After a diagnosis of nightmare disorder, individual psychological talking therapies are recommended as treatment.
One such treatment is called new dream therapy. It involves rehearsals of changed storylines of the frequently occurring dreams. This is done to reduce distressing parts of the dream story, thus trying to eliminate nightmare episodes.
These therapies are based on the principles of cognitive behaviour therapy (CBT). Medications alone help sometimes. Practising sleep hygiene regularly and relaxation training could help restore quality sleep, and in turn, reduce nightmares.
Lucid dream therapy based on Tibetan dream yoga has also been tried, where the person learns to develop an extraordinary ability to become conscious of the dream whilst in the dream. This enables him to control and change the course of the dream itself.
Engaging in a healthy lifestyle, joyful activities, having optimistic positive thoughts throughout the day, and recalling positive events before going to bed, can help experience enjoyable dreams.
Dreams have cultural, religious and spiritual significance. Elders in the family would often advise you to practise certain behaviours before going to bed. For instance, praying before sleeping, to avoid bad dreams.
In conclusion, it is absolutely normal to experience dreams, but not frequent nightmares.
(The author is consultant psychiatrist, Ad hoc faculty at NIMHANS, Bengaluru)