On this occasion I would like to talk to you about the dream; its functions, its phases, its implication in our psychological health, as well as some of the most common alterations and, finally, leaving you with some sleep hygiene suggestions. All this accompanied by a masterful video made by the BBC and some other resources.
We spend a third of our existence (220,000 hours in 60 years) with our eyelids closed, in a mysterious and unknown state that we call sleep. But be careful! All of this time is active time and many changes occur in both mental activities and bodily functions, and all of them are of enormous importance for our physical and psychological balance. In short, it performs a restorative function for our body, helping to recover energy, thermoregulation, consolidate learning and memory, among many other functions.
In the sleep period we find two stages, called slow sleep phase or NON-REM, and fast sleep phase or REM (acronyms that correspond to its name in English: Rapid Eye Movements or rapid eye movements). He NON-REM sleep, is divided, in turn, into four phases with different characteristics. These phases alternate cyclically while we remain asleep (approximately every 90/100 minutes, a new sleep cycle begins in which the last 20 or 30 minutes correspond to the REM phase).
- Phase I. It is the light sleep phase, in which people are still able to perceive most stimuli (auditory and tactile). Sleep in phase I is little or not at all restorative. Muscle tone decreases compared to the waking state, and slow eye movements appear.
- Phase II. In this phase, the nervous system blocks the access routes for sensory information, which causes a disconnection from the environment and therefore facilitates the activity of sleeping. Here sleep is partially restorative and occupies around 50% of sleep time in adults. Muscle tone is lower than in phase I, and eye movements disappear.
- Phase III. It is a deeper sleep (called DELTA), where the sensory block is intensified. If we wake up during this phase, we will feel confused and disoriented. In this phase, there is no dreaming, there is a 10 to 30 percent decrease in blood pressure and respiratory rate, and the production of growth hormone increases. Muscle tone is even more reduced than in phase II, and there are no eye movements either.
- Phase IV. It is the deepest phase of sleep, in which brain activity is slower (predominance of delta activity). Like phase III, it is essential for the physical and, especially, mental recovery of the body (phase III and IV deficits cause daytime sleepiness). In this phase, muscle tone is greatly reduced. It is not the typical phase of dreams, but sometimes they can appear, in the form of images, lights, figures… without a plot line.
- REM phase: It is also called paradoxical dream, due to the contrast between muscle atony (total relaxation) typical of deep sleep, and the activation of the central nervous system (a sign of wakefulness and alertness). In this phase, dreams are presented, in the form of a narrative, with a plot thread, even if it is absurd. The electrical brain activity of this phase is rapid. Zero muscle tone (muscle atonia or paralysis) prevents the sleeping person from materializing their dream hallucinations and from harming themselves. The most typical alterations of this phase are nightmares, REM sleep without atonia and sleep paralysis.
Regarding the ideal amount, there is no very reliable standard measure because not all of us have the same needs. Some are great with five hours and others with ten, and both extremes are normal. Young people, athletes, people who make great physical or mental efforts, those who have a larger constitution usually need more.
As a curious anecdote, I tell you that Edison used to sleep an average of five hours, while Einstein used to sleep ten hours. What matters in the end is quality rather than quantity.
If you value articles like this, consider supporting us by becoming a Pro subscriber. Subscribers enjoy access to members-only articles, materials, and webinars.
What is certain is that if we stay awake for a very long period of time or if we try to suppress sleep continuously, alterations will appear in our body, for example: increased anxiety and irritability, problems with attention, concentration and memory, loss of reflexes, depression and in severe cases even death.
WHAT MATTERS IN THE END IS THE QUALITY MORE THAN THE QUANTITY
As we have seen, not getting frequent and deep sleep causes serious problems. We can all “lose sleep” occasionally, this can be for various reasons, for example: situations that involve stress, health problems and medications, too many hours of work/shift work, drinking alcohol, eating too close to bedtime , etc. However, most of these situations are specific. When this is not the case, when the problem is very constant, we fall asleep during the day, we snore or we find ourselves emotionally unstable, then we have to take measures, as they can be indicators of sleep disturbances. Let’s see what the sleep problems are according to the DSM-V
The most recent edition of the DSM (Diagnostic and Statistical Manual of Mental Disorders) of the American Psychiatric Association, is the fifth (DSM-V) and proposes the following classification in its section “Sleep-wake disorders”:
Insomnia disorder
We speak of an insomnia disorder if we have favorable conditions for sleeping and yet dissatisfaction with the quantity or quality of sleep predominates; either difficulty initiating or maintaining sleep. This alteration causes clinically significant discomfort or impairment in social, occupational, educational, academic, or other important areas of behavior and functioning. And what’s more, it occurs at least three nights a week for a minimum of three months.
There are many factors that intervene in the appearance and maintenance of insomnia. Among the most important are the psychological ones (tendency to dwell on things, difficulties in managing negative emotions, erroneous beliefs in relation to sleep, with the consequent inadequate habits), stress and the fear of not sleeping.
The DSM-V also specifies the duration, so we would have:
- Episodic: symptoms last at least one month but less than three months
- Persistent: symptoms last three months or more
- Recurrent: two or more episodes within a year
Keep in mind, of course, that in any of the disorders described here the absence of medication, drugs, or any type of substance that alters our physiology is evident.
Hypersomnia disorder
We could suffer from a hypersomnia disorder if we experience excessive sleepiness (hypersomnia) despite having slept for a main period that lasts at least seven hours, adding to this recurrent periods of sleep or a prolonged main episode of sleep of more than nine hours a day that It is not restorative (that is, we do not rest), or difficulty being fully awake after a sudden awakening, or all of the above.
NOT GETTING CONTINUOUS AND DEEP SLEEP CAUSES SERIOUS PROBLEMS
Hypersomnia occurs at least three times a week for at least three months and is accompanied by significant distress or impairment in cognitive, social, occupational, or other important areas of functioning.
Duration and severity are also specified in the DSM-V. In terms of duration we would have:
- Sharp: duration less than one month
- Subacute: duration of 1–3 months
- Persistent: duration greater than three months
As for severity, it is based on the degree of difficulty in maintaining alertness during the day and thus we would have:
- Mild: difficulty staying alert during the day, 1–2 days/week
- Moderate: 3–4 days/week
- grave: de 5–7 days/week.
Narcolepsy
It is the most serious case of hypersomnias, it is a sleep disorder that causes excessive sleepiness and uncontrollable and frequent sleep attacks during the day. Two other criteria that accompany the diagnosis are the presence of cataplexy (a loss of muscle tone and sudden weakness ) and hypocretin deficiency. These episodes must have occurred at least three times a week for the last three months.
About half of individuals with narcolepsy experience sleep-like states between sleep and wakefulness (hypnagogic hallucinations). Narcolepsy is caused by low concentrations of chemical messengers in the brain (dopamine and norepinephrine), and by genetic factors.
The DSM-V also specifies: narcolepsy without cataplexy but with hypocretin deficiency, narcolepsy with cataplexy but without hypocretin deficiency, autosomal dominant cerebellar ataxia, deafness and narcolepsy, autosomal dominant narcolepsy, obesity and type 2 diabetes, and secondary narcolepsy. to another medical condition.
And the severity is indicated by the presence of cataplexy, since mild (less than one a week) until serious (daily and drug resistant).
Sleep disorders related to breathing
Characteristic of these disorders are repeated episodes of upper airway obstruction or collapse that occur while we sleep, due to the airway narrowing, blocking, or becoming flexible.
Apnea is defined as a temporary interruption of breathing lasting more than ten seconds causing collapse, either by reduction (hypopnea) or by complete arrest (apnea) of the air flow towards the lungs, and can produce, among other effects, a decrease in oxygen levels and an increase in the level of carbon dioxide (CO2) in the blood, as well as a small, often subconscious awakening (arousal). , which allows normal breathing to be recovered until the next episode occurs. Breathing usually returns to normal, sometimes with a loud snoring or a choking sound.
The length of the pauses can vary from a few seconds to several minutes, and typically occur between 5 and 30 times per hour, although it is true that most people experience brief episodes of apnea while sleeping. If the pauses occur between 10 and 20 times per hour, the disorder is considered mild; if it occurs between 20 and 30 times per hour, moderate and if they occur more than 30 times per hour it is classified as severe.
In the updated version of the manual we find the classification of these disorders into three types: