Simplify the following text for a Grade 8 native English-speaking person.
Original: In a study of 54 BDD patients who were randomly assigned to Cognitive Behavior Therapy or no treatment , BDD symptoms decreased significantly in those patients undergoing CBT .
Simplified: In a study of 54 patients with BDD , some of them had Cognitive Behavior Therapy , and some had no treatment . BDD symptoms decreased a lot in those patients undergoing CBT .