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Exploring The Psychiatry of Dreaming  

How we sleep and why we dream.

Key points

  • Sleep and dreaming are complex processes essential for normal biomental functioning.
  • Sigmund Freud was the first psychiatrist to examine and delineate a coherent theory of sleep and dreaming.
  • Modern electroencephalographic research has outlined sleep architecture and the stages of dreaming.
  • Sleep medicine suggests sleep as a significant vital sign for health, well-being, and studying disorders.
Icebergs, Surface and Submerged, by Frank John Ninivaggi, 2020, oil on canvas
Source: Icebergs, Surface and Submerged, by Frank John Ninivaggi, 2020, oil on canvas

Sleep is a complex process involving various regulatory events that increase brain activation and cellular metabolism, and dreaming is essential for normal physiological functioning. The field of psychiatry focuses on the clinical and subjective experiences of sleeping and dreaming. Biological and mental, i.e., biomental, areas are addressed. Sleep medicine identifies and treats disorders that interfere with typical sleep patterns and their restorative benefits.

Sleep and Dream Experience

The scientific study of dreaming began with Sigmund Freud in Chapter VI of his seminal work, The Interpretation of Dreams (1900), which attempted to explain in mental or psychological language why we sleep and to understand its meaning.

Freud's colleagues likened his idea of consciousness to an iceberg, where most of it was submerged beneath the waterline. The tiny, visible portion above represented conscious awareness, while the more significant parts that remained unseen were non-conscious yet dynamically active, steering conscious thoughts, feelings, and actions.

His "continuity hypothesis" linking all portions of consciousness—awareness to unawareness—suggested that a "dream work" conceals the entire psychological meaning of a dream, yet with analysis, could disclose a "royal road to the unconscious."

The "materials" used to do this work were "dream residues" of the day—thoughts and emotions of waking life and bodily sensations experienced during sleep. These residues are the manifest dream images remembered or forgotten upon awakening; prompting their appearance are the latent dream contents, unconscious "thoughts" in the repressed mind. Freud stressed that the essence of the dream is its dream work proper, the secondary revision of latent contents transforming into the manifest "furniture" of the dream images. At the end of his life, Freud said that "dreams protect sleep." Current scientific studies show that non-REM sleep serves this function and is also a source for dreaming in addition to REM sleep.

The Electrophysiology of Sleep and Dreaming: EEG Patterns

In 1951, Nathaniel Kleitman and Eugene Aserinsky at the University of Chicago, attempting to discover how we sleep, conducted groundbreaking research on sleep medicine by examining eye movements during sleep. This discovery identified a new sleep state known as "rapid eye movement," or REM, and its correlation with dreaming. A seminal paper in 1953 presented their findings. In 1957, William Dement and Nathaniel Kleitman proposed a new sleep cycle classification that introduced NREM (non-REM) sleep stages that progressively deepened, were interspersed with periods of REM sleep, and were repeated four to six times throughout the night. This classification is still in use today, albeit with modifications. The electrophysiological basis of human sleep uncovered by Kleitman, Aserinsky, Dement, and their colleagues has been the foundation for sleep research for over half a century.

The prevailing method for investigating and characterizing sleep and dreaming is through scientific and descriptive research of the biological "how" of sleep. These methods involve using electrophysiological studies, where electrodes are affixed to the scalp to map the electrical waves or oscillations into specific frequency ranges. For instance, the frequency range of four to seven Hertz (a unit of frequency of one cycle per second) is called "theta." EEG oscilloscopes reveal five distinct brain wave oscillations: 1.) gamma, linked to mental concentration, 2.) beta, associated with external attention and anxiety, 3.) alpha which indicates relaxation, 4.) theta, linked to deep relaxation and light sleep, and 5.) delta associated with deep sleep.

Sleep is categorized into two types: 1.) non-rapid eye movement and 2.) rapid eye movement sleep. NREM is further divided into stages ( I, II, III, and IV) based on changes in EEG patterns. Stages III and IV are usually grouped together as "slow wave sleep" (SWS) or deep sleep. Stage III delta wave is considered the deepest and most restorative.

During the transition from the relaxed and awake state to stage I NREM sleep, lasting about one to seven minutes, the alpha waves change to theta waves. As sleep progresses, sleep spindles and K-complexes join the theta waves until delta waves, or slow wave sleep, become dominant, marking the emergence of NREM stages III and IV (deep sleep) over the next 20 to 60 minutes.

NREM and REM sleep alternate in cycles lasting about 90-100 minutes, with four to six cycles per night. In young adults, NREM sleep accounts for 75-90 percent of sleep time, with 3-5 percent in stage I, 50-60 percent in stage II, and 10-20 percent in stages III and IV. As sleep progresses, stage II becomes most of NREM sleep, and stages III and IV begin to disappear. The figures given are approximations from the Institute of Medicine on Sleep Medicine and the NIH (2006).

REM sleep comprises 10-25 percent of sleep time. REM activity begins approximately 90 minutes after falling asleep. The first REM cycle lasts about ten minutes. The average length of the first NREM-REM sleep cycle is 70 to 100 minutes. The second and later cycles are longer lasting—approximately 90 to 120 minutes. In normal adults, REM sleep increases as the night progresses and is the longest in the last one-third of the sleep episode. Most dreams occur during the last two hours before waking. Studies confirm that dreaming can occur both during REM and NREM sleep, especially NREM stage II. However, REM dreaming is more vivid, intense, and emotionally charged.

Although all senses contribute, most dreams are visual and in black and white, but some can be in color. During REM sleep, the intensity of dreams is heightened, and emotional memories consolidate several hours before awakening. Studies show that negative emotions, such as anxiety and fear, are more commonly experienced in dreams than positive ones. Nightmares tend to occur during REM sleep. The dreamer is usually the central observer, with others taking part randomly. Dreams are often dramatic because of their intense and vivid emotional elements.

According to the National Sleep Foundation and Centers for Disease Control, children aged six to 12 should aim for nine to 12 hours of sleep, teenagers should aim for eight to ten hours of sleep, adults aged 18 to 61 are recommended to sleep seven or more hours, people aged 61 to 64 should aim for seven to nine hours of sleep, and those aged 64 and above are advised to sleep seven to eight hours.

Neurophysiological Explanations for Why We Dream

  • Memory consolidation enhances cognitive abilities by strengthening memories and improving information recognition and recall.
  • Emotion processing involves practicing the management of feelings by reconstructing them during REM theta oscillations or waves that are deeply relaxing.
  • Event review and replay involve problem-solving and clearing and rearranging recent events.
  • Brain detoxification with the removal of harmful substances, such as beta-amyloid.
  • Other potential purposes are yet undiscovered.

Sleep-Wake Disorders and When Dreams Turn Into Nightmares

Sleep disturbances are classified into six primary categories by psychiatry, following the American Psychiatric Association's diagnostic system (DSM-5-TR). These categories include:

  1. Insomnia
  2. Hypersomnia
  3. Narcolepsy
  4. Sleep-Related Breathing Apnea and Hypo-apnea
  5. Circadian Rhythm Sleep-Wake disorders
  6. Parasomnias and Sleep-Related Movement disorders

Sleep Hygiene Practices

Sleep hygiene practices improve sleep quality. They are important because they prevent and minimize sleep disorders while promoting biopsychosocial well-being. Good sleep hygiene involves adopting practical steps so they become daily habits. These include: maintaining a regular bedtime and waking time, avoiding heavy meals and excessive caffeine intake close to sleep, and engaging in regular physical activity. Creating a comfortable sleep environment means keeping the bedroom cool, dark, and quiet and limiting screen time for at least two hours before sleep. Reading and eating in bed should be discouraged, and consuming alcohol within six hours of sleep is not recommended. Daytime naps should be limited to no more than 20 minutes between noon and 3 p.m.

Relaxation and breathing exercises are essential to mindful wellness and help promote restorative sleep.

The progressive muscle relaxation technique involves deliberately tensing different muscle groups for five to six seconds and then relaxing them for 20 to 30 seconds. The process begins from the head and moves down to the feet.

Adding deep breathing exercises amplifies relaxation and may prompt theta and delta waves preparatory for lowered anxiety and restorative, deeper sleep. Historically, deep breathing has been called "watching the breath." To practice this technique, one can sit upright in a chair or while in bed, closes the eyes, and focuses on breathing while placing a hand on the abdomen/belly. The aim is to feel the abdominal area rise and fall, thus promoting slow breathing. Gently inhaling through the nose for about four to six counts, holding the breath for six to seven counts, and slowly exhaling through the mouth or nose for longer than the inhalation, for a count of eight, is optimal. These instructions are beneficial for beginners. One can enhance sleep quality and overall well-being by incorporating these habits into daily routines.


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