Psychological sleep disorders: Pathology review


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Psychological sleep disorders: Pathology review

Psychological disorders

Mood disorders

Major depressive disorder


Bipolar disorder

Seasonal affective disorder

Premenstrual dysphoric disorder

Anxiety disorders

Generalized anxiety disorder

Social anxiety disorder

Panic disorder



Obsessive-compulsive disorders

Obsessive-compulsive disorder

Body focused repetitive disorders

Body dysmorphic disorder

Stress-related disorders and abuse

Post-traumatic stress disorder

Physical and sexual abuse

Psychotic disorders

Schizoaffective disorder

Schizophreniform disorder

Delusional disorder


Cognitive and dissociative disorders



Dissociative disorders

Eating disorders

Anorexia nervosa

Bulimia nervosa

Personality disorders

Cluster A personality disorders

Cluster B personality disorders

Cluster C personality disorders

Somatoform and factitious disorders

Somatic symptom disorder

Factitious disorder

Substance use disorders and drugs of abuse

Tobacco dependence

Opioid dependence

Cannabis dependence

Cocaine dependence

Alcohol use disorder

Sleep disorders


Nocturnal enuresis


Night terrors

Narcolepsy (NORD)

Sexual dysfunction disorders

Erectile dysfunction

Male hypoactive sexual desire disorder

Orgasmic dysfunction

Female sexual interest and arousal disorder

Genito-pelvic pain and penetration disorder

Pediatric disorders

Attention deficit hyperactivity disorder

Disruptive, impulse control, and conduct disorders

Learning disability

Fetal alcohol syndrome

Tourette syndrome

Autism spectrum disorder

Rett syndrome

Shaken baby syndrome



Psychiatric emergencies


Serotonin syndrome

Neuroleptic malignant syndrome

Psychological disorders review

Mood disorders: Pathology review

Amnesia, dissociative disorders and delirium: Pathology review

Personality disorders: Pathology review

Eating disorders: Pathology review

Psychological sleep disorders: Pathology review

Psychiatric emergencies: Pathology review

Drug misuse, intoxication and withdrawal: Hallucinogens: Pathology review

Malingering, factitious disorders and somatoform disorders: Pathology review

Anxiety disorders, phobias and stress-related disorders: Pathology Review

Trauma- and stress-related disorders: Pathology review

Schizophrenia spectrum disorders: Pathology review

Drug misuse, intoxication and withdrawal: Stimulants: Pathology review

Drug misuse, intoxication and withdrawal: Alcohol: Pathology review

Developmental and learning disorders: Pathology review

Childhood and early-onset psychological disorders: Pathology review


Psychological sleep disorders: Pathology review

USMLE® Step 1 questions

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USMLE® Step 1 style questions USMLE

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A 25-year-old graduate student comes to the physician for evaluation of excessive sleepiness over the past year. He is often sleepy during the day and frequently falls asleep during class. These episodes occur nearly daily and have been negatively affecting his grades. The patient goes to bed at 10 PM and wakes up at 7 AM. Last week, during an argument with his partner, the patient suddenly felt weak in the legs and collapsed onto the floor. The patient does not consume alcohol or recreational drugs. He has not experienced a loss of interest in his normal activities and does not have suicidal ideations. Vitals are within normal limits. Physical examination is unremarkable. Which of the following additional features is likely to be present in this patient?  

Memory Anchors and Partner Content


Content Reviewers

Antonella Melani, MD


Antonia Syrnioti, MD

Evan Debevec-McKenney

Tina Collins

Talia Ingram, MSMI, CMI

A 31 year old male named Hercules comes to the clinic complaining of excessive daytime sleepiness over the past year, despite getting a regular 7 to 9 hour sleep every night. This has recently started to interfere with his job, since he keeps dozing off at his desk, during meetings, or even while talking on the phone. Hercules is also concerned because he sometimes has very vivid dream-like sensations right before falling asleep, like seeing other people in the room. On further questioning, Hercules also mentions that when he gets really nervous or excited about something, he feels as if he cannot move his legs and might even fall down. Past medical history and physical examination are both unremarkable.

Based on the initial presentation, Hercules seems to have some form of sleep disorder. Many of us can have trouble falling asleep or may sleep too much from time to time, usually because of stress or a temporary illness. But when sleep problems become a regular occurrence and interfere with daily life, that’s a sign of a sleep disorder. For your exams, remember that sleep disorders are usually caused by factors that interrupt the sleep cycle, which is a period of sleep that lasts about 90 minutes and is divided into four stages. The first three stages make up non-REM or NREM sleep, which stands for non-rapid eye movement. So usually during non-REM sleep, our eyes don’t move much or at all. However, keep in mind that the voluntary muscles of the body may still be active. NREM sleep accounts for roughly 80% of the sleep cycle, and across the three stages of NREM, we move from very light sleep during Stage 1, to very deep sleep in Stage 3. This is followed by Stage 4, which is known as rapid eye movement or REM sleep, and accounts for the last 20% of the sleep cycle. During REM sleep, the eyes dart around really fast, and this is where dreaming occurs and memories are consolidated. During REM sleep, the voluntary muscles of the body are paralyzed, probably to prevent people from acting out their dreams. Now, REM sleep is then followed again by non-REM sleep, and over the course of the night, there are four or five of these sleep cycles.

Okay, now for your test, the most high yield sleep disorders include sleep terror disorder, enuresis, and narcolepsy.

Let’s start with sleep terror disorder.

For your exams, remember that this is typically triggered by stress or fatigue, fever, or sleep deprivation, and is most common in children. So, in sleep terror disorder, individuals partially wake up during deep sleep or stage 3 of NREM sleep, and suddenly start screaming or crying. And this turns on the sympathetic nervous system, which can lead to mydriasis or dilated pupils, tachycardia or rapid heart rate, tachypnea or rapid breathing, and sweating. What’s extremely high yield is that individuals usually return to sleep right afterwards, and the next day they have no recollection of the episode. For your exams, make sure you're able to set sleep terrors apart from nightmares, which typically occur during REM sleep, and individuals wake up right away and the next day, they are able to recall the episode! Okay, now, because sleep is disrupted, people with sleep terror disorder often feel chronically fatigued, which can lead to distress and impairment in a person’s life. Good news is that sleep terror disorder is typically self limited and tends to resolve spontaneously by puberty, so no treatment is needed.


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  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "Diagnostic and Statistical Manual of Mental Disorders" NA (1980)
  5. "Sleep disorders" Neurobiology of Psychiatric Disorders (2012)
  6. "Family history of REM sleep behaviour disorder more common in individuals affected by the disorder than among unaffected individuals" Evidence Based Mental Health (2013)
  7. "Sleep: A Novel Mechanistic Pathway, Biomarker, and Treatment Target in the Pathology of Alzheimer's Disease?" Trends in Neurosciences (2016)

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