Psychiatrycommon
A 47-year-old truck driver is referred by his general practitioner with insomnia and low mood after two months of exhaustion. He is in bed for nine hours a night and rarely wakes, yet never feels rested, and has twice nodded off at traffic lights. His wife moved to the spare room a year ago because of the noise, and says he goes quiet for a while and then gasps. She has never seen his legs jerk. He still enjoys his weekends, does not wake early, and drinks no alcohol. His body mass index is 34 kg/m2. Which one of the following best explains his symptoms?