A sleep disorder with complex motor activity during slow-wave sleep, including getting out of bed and possibly walking.

• A. Opioids
• B. REM sleep
• C. Shift work
• D. Somnambulism

Answer: (D)

Sleepwalking is a parasomnia where a person performs complex motor activities during deep, slow‑wave sleep and may get out of bed to wander. These events happen during non‑REM sleep, usually early in the night, and the person often has little or no memory of the episode and can be difficult to awaken. This pattern distinguishes it from REM sleep–related disorders, where movements occur during dreams in REM sleep. The other options don’t describe a sleep disorder characterized by action during slow‑wave sleep.