The product is already in the market and has been for a while....

The product is already in the market and has been for a while. The clinical trials was to test for its effectiveness in Depression.

There is nothing wrong with conducting a clinical trial to check the effectiveness of an existing product on a new condition.

Think of it like this, There is a new study to test the effectiveness of Panadol to treat depression.... Panadol does not need to be removed from the market while the study is taking place. It has already been approved for safety.