Which of the Following Is an Incorrect Statement Concerning Electroconvulsive

Which of the following is an incorrect statement concerning electroconvulsive therapy?

A) no one is certain exactly why the treatment works
B) people who receive the treatment have a relatively high relapse rate
C) researchers do not show concern the procedure might cause permanent brain damage
D) the procedure can produce side effects, such as confusion or loss of memory, although they are usually not serious