MCAT® ExamPsychological, Social, and Biological Foundations of BehaviorHard
A patient complains of difficulty falling asleep, frequent awakenings during the night, and feeling unrested despite spending adequate time in bed. These symptoms have been present for several months and are causing significant distress and impairment in daily functioning. Before diagnosing a sleep disorder, a clinician would typically rule out other medical conditions and substance use. This constellation of symptoms is most consistent with which of the following primary sleep disorders?
- ARestless Legs Syndrome
- BInsomnia Disorder
- CSleep Apnea
- DNarcolepsy
Show answer & explanationAnswer & explanation
Correct answer: B. Insomnia Disorder
Insomnia disorder is characterized by persistent difficulty with sleep initiation, duration, consolidation, or quality that occurs despite adequate opportunity for sleep and results in daytime impairment. The patient's symptoms directly match this definition.
Why the other options are wrong
- A. Restless Legs Syndrome involves an uncomfortable urge to move the legs, typically worsening in the evening, which can disrupt sleep but is not the primary diagnostic category for these symptoms.
- C. Sleep apnea involves repeated cessation of breathing during sleep, leading to awakenings and daytime sleepiness, but the primary complaint here is difficulty falling/staying asleep and feeling unrested.
- D. Narcolepsy involves irresistible urges to sleep during the day, often with cataplexy, which is not described here.
Insomnia Disorder
A sleep disorder characterized by dissatisfaction with sleep quantity or quality, associated with difficulty initiating or maintaining sleep.
- Symptoms occur at least 3 nights per week for at least 3 months
- Causes significant distress or impairment in functioning
- Not better explained by another sleep disorder or mental/medical condition
Memory trick: In-somnia means 'no sleep' for months.