This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Seedatives & Hyponotics, Subject name: Pharmacology
Modafinil is used as an adjunct in the treatment of? 
Select and explain. 
A. Sleep apnea syndrome, B. Narcolepsy, C. ADHD, D. Shift work disorder
A: Sleep apnea syndrome
Answer: A: Sleep apnea syndrome 
Explanation: ANSWER: (A) Sleep apnea syndrome REF: Harrison's 18th ed ch: 27FDA approved indications of modahnil:Drug of choice: Narcolepsy and shift work disorderAdjunctive treatment of sleep apnea syndromeOff label uses (where use is doubtful)ADHDDepressionBipolar disorderFatigueDepersonalisation disorderCognitive enhancement