This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mood Disorders, Subject name: Psychiatry
Which of the following indications of deep brain stimulation is not FDA approved? 
Select and explain. 
A. OCD, B. Major depression, C. Parkinsonism, D. Dystonia
B: Major depression
Answer: B: Major depression 
Explanation: FDA approved indications for deep brain stimulation are: a. Parkinson's disease and essential tremors b. Dystonia c. Obsessive compulsive disorder