Simplify the following text for a Grade 12 native English-speaking person.
Original: 74 subjects were enrolled in a placebo-controlled study group to evaluate the efficiency of fluoxetine hydrochloride ( Prozac ) ; patients were enrolled in a 12-weeks , double-blind , randomized study .
Simplified: 74 subjects were enrolled in a placebo controlled study group to evaluate the efficiency of fluoxetine hydrochloride , a SSRI drug . Patients were randomized to receive 12-weeks of double-blind treatment with fluoxetine or the placebo .