Which of the following disorders is commonly evaluated through a sleep study?

Sleep apnea is a disorder commonly evaluated through a sleep study (polysomnography) because it directly affects breathing patterns during sleep. This condition is characterized by repeated interruptions in breathing, which can lead to significant health issues such as cardiovascular problems, daytime fatigue, and impaired cognitive function. A sleep study helps to identify the severity and type of sleep apnea, whether it be obstructive, central, or complex, by monitoring various physiological parameters like airflow, blood oxygen levels, and muscle activity throughout the night. The other conditions mentioned, while they may have sleep disturbances as a component, are not primarily assessed through polysomnography, which focuses on the physiological aspects of sleep rather than psychological diagnoses.