Sleep disorders: what they are and how to recognize them?

Sleep disorders: what they are and how to recognize them?

Publication date: 10-05-2023

Updated on: 10-05-2023

Topic: Mental health

Estimated reading time: 1 min

Sleep represents a very important and indispensable biological function for all living things. With the team of the Clinical Psychology Service of Policlinico San Donato we've investigated the correlation between sleep and the brain, psychological aspects of sleep deprivation, and the effects on mood that can result.

Together with Dr. Valentina Fiolo, Dr. Silvana Pagliuca and Dr. Enrico G. Bertoldo, we find out specifically what sleep disorders are, how to recognize them, and which health professionals to turn to.

Benefits of sleep

Although falling asleep involves general deactivation, biologically important events occur during sleep such as the recovery of energy, both physical and mental, and the restoration of strength. In the literature, numerous theories have highlighted how sleep is, in addition, related to cognitive functioning (think of learning processes and memory consolidation) and motor functioning. In general, sleep performs numerous functions:

  • recovery and rest understood as general deactivation from continuous internal and external stimuli;
  • preservation and conservation of available energy;
  • ecological function;
  • immunological function;
  • thermoregulatory function;
  • neuronal integrity at the level of synapses and networks.

How many hours it is recommended to sleep

The distribution of sleep hour requirements varies with age. In infancy, the required hours of sleep range from 16 to 20 hours per day, with sleep distributed irregularly and discontinuously over the 24 hours and determined mainly by the feeding needs of the youngest infants. 

From the 6th month of life, there is a gradual consolidation of sleep in the night period. At the age of 10 years, the total sleep period is 9-10 hours, and in adolescence it is recommended to sleep about 7 hours.

In adulthood, also complicit with the rhythms of work and daily life, there is usually a further reduction, so it is recommended to sleep about 6 1/2 hours. 

Sleep deprivation and related disorders

Sleep, wakefulness and alertness are primary functions of the encephalon (brain, from the brainstem and cerebellum): any pathology or alteration in the encephalon can, therefore, have repercussions and negative effects on sleep. Physiological sleep is closely related to neuronal plasticity: sleep deprivation may interfere with hippocampal activity and contribute, albeit in part, to the etiology of depressive phases. 

Even at the behavioral level, states of work and social stress, associated with worries and intrusive thoughts, can negatively affect sleep by interrupting its normal flow up to the most acute cases of insomnia. 

When persistent and protracted over time, insomnia can promote the onset of psychiatric disorders due to important changes at the neurophysiological and neuroendocrine levels. It constitutes, in fact, one of the quintessential symptoms of most mental disorders, and the treatment of it is of paramount importance in both the process of prevention and care and treatment.  

Below are some of the disorders that have a correlation with sleep: 

  • Anxious states and personality disorders. Generalized anxiety or anxiety related to panic attack disorders or, again, related to phobic and obsessive-compulsive disorders is closely related to sleep in that the psychological and physiological arousal (awakening) state typical of anxiety strongly disturbs sleep and, likewise, disturbed sleep accentuates the state of anxiety. Anxiety-induced insomnia is predominantly manifested by a difficulty in initiating sleep and/or maintaining it.
  • Depression and mania. In depressive states, sleep is impaired due to frequent awakenings and the earliness of final awakenings, while in contrast to anxiety, the falling asleep phase is less involved.
  • Stress-related disorders. All related stress disorders have a major impact on sleep, as physiological state of activation remains preventing the individual from easing daily tensions.  

What are sleep disorders? What types there are?

Sleep disorders include all those disorders that impair both the quantity and quality of sleep with major impacts on overall health and quality of life. The International Classification of Sleep Disorders (according to the American Academy of Sleep Medicine, ICSD 3,2014) includes 6 diagnostic classes:

  • insomnia;
  • sleep breathing disorders;
  • hypersomnia of central origin;
  • circadian rhythm disorders;
  • parasomnias;
  • movement disorders in sleep.

We analyze the most common sleep disorders with specialists.

Obstructive sleep apnea syndrome (OSA)

Obstructive sleep apnea syndrome (OSA) involves frequent interruptions in respiratory flow due to partial or complete airway obstruction during sleep. The syndrome can affect cardiovascular, respiratory and nervous systems. Obstructive apnea is sometimes associated with arterial hypoxemia and causes cardiac ischemia. Symptoms of OSA can be:

  • habitual and persistent snoring every night for at least 6 months;
  • pauses in breathing;
  • awakenings with choking sensation;
  • daytime sleepiness.

Therapies can be behavioral, postural, orthodontic, or prosthetic-ventilatory (CPAP).

Restless legs syndrome (RLS)

Restless legs syndrome (RLS) is a neurological disorder that involves the need to move the legs during the night to relieve pain and discomfort. It can result in high cardiovascular and cognitive risk. The condition tends to be seasonal: it appears in summer and then tends to become chronic. Treatment is usually pharmacological.


Parasomnias are a subcategory of sleep disorders involving all those unwanted movements that may occur during falling asleep, whole sleeping, or upon awakening. Parasomnias are divided into:

  • NREM-related parasonnias (NON REM sleep);
  • REM-related parasomnias (REM sleep).

NON REM sleep-related parasomnias (REM = Rapid Eye Movement) may consist of episodes of incomplete awakening, low responsiveness to stimuli, and little or no memory of the episode. These disorders include:

  • confusional awakenings, with possible tachycardia, tachypnea (rapid breathing), mydriasis (dilated pupils), and sweating;
  • somnambulism;
  • pavor nacturnus (night terrors), whereby the subject screams in sleep and has low reactivity to external stimuli. The episode lasts an average of 30 seconds to 3 minutes, and upon awakening subjects may have no memory of the source of the terror.

REM sleep is a stage of sleep characterized by rapid eye movements, increased breathing, heart rate, pressure and muscle atony (functional paralysis of muscles). REM sleep-related parasomnias include:

  • REM sleep behavior disorder, characterized by movements during REM phase, in reaction to a dream, caused by lack of muscle atonia. The disorder is more common in those taking certain antidepressants and in those over 50;
  • sleep paralysis, characterized by the sensation of muscle atrophy during sleep or upon awakening. The episode lasts about a few minutes. This disorder can cause profound states of distress;
  • nightmare disorder, often a component of posttraumatic stress disorder, is characterized by the experience of recurrent, vivid nightmares with themes related to threats to survival.

Delayed and early sleep phase syndrome

Delayed sleep phase syndrome is characterized by a shift of the sleep period to the morning hours, with difficulty or inability to comply with social commitments; if these are forcibly maintained, this results in a decrease in daily sleep hours resulting in daytime sleepiness and subsequent recovery of sleep on holidays.

Early sleep phase syndrome, which tends to be chronic, is characterized by an early sleep period in the evening hours and an early awakening in the morning hours.


Insomnia is a symptom reported by the patient as a difficulty in falling asleep, maintaining sleep with frequent awakenings or definite early awakenings. Importantly, insomnia is defined by the condition of 'disturbed sleep' and the patient's subsequent inability to recognize sleep as restorative. It is the most common of all sleep disorders; it is often a symptom of underlying medical, psychiatric and neurological conditions. It may be secondary to other sleep disorders or be drug-induced. 

Continued insomnia is associated with behavioral adaptations, such as staying awake in bed, which negatively affect the development of sleep alteration to the point of connoting a picture of chronic insomnia, which exacerbates the already high levels of daytime stress and further potentiates the vicious cycle.

It is, finally, well known that sleep disturbances can occur in cardiovascular disease and that they mainly affect patients with ischemic heart disease, myocardial infarction, or congestive heart failure.

The pain typical of ischemic heart disease may wake the patient and thus result in decreased sleep efficiency.

How to recognize them

The most common symptoms that signal the presence of a sleep disorder are: 

  • daytime fatigue and listlessness;
  • lack of air;
  • morning headaches;
  • difficulty concentrating;
  • abrupt awakenings during the night. 

These effects can be confirmed through instrumental, noninvasive, and easy-to-apply examination such as polysomnography.

Which health professionals to turn to if you suffer from sleep disorders?

In the presence of a sleep disorder, when 2 or more symptoms become persistent and compromise the quality of life, after having made all the relevant specialist examinations to frame from a biological and physiological point of view, one can turn to a psychologist who, thanks to his specific skills, is able to facilitate an accurate diagnostic framing, essential to establish the presence or absence of a sleep disorder, on the basis of which a therapeutic path of taking charge and follow-up of the complex and articulated symptomatology is structured and indicated.

Tools used to treat sleep disorders include validated and standardized relaxation techniques and imagery techniques.

The treatment of insomnia and symptoms, in general, can have a preventive and protective effect with respect to the possible future onset of psychopathology, while in disorders that are already overt, as in the case of psychiatric disorders, it can positively influence the course of the pathology and have a preventive effect of possible relapse. In some cases, such as those in which a depressive disorder is present, the use of antidepressant psychotropic drugs combined with hypnotic drugs may also be integrated, with varying efficacy depending on the severity of depression and the type of insomnia.

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