Motivating a teenager with depression is hard. However, one thing you can do is to listen without judgment and be there. Make sure your teen feels that they are not alone in this journey. Your constant support, love, and presence can significantly help in the recovery process.
At the same time, consult a trustworthy expert for advice on how to approach your teen. Doctors may recommend individual, group, or family counseling, therapies, or medicines to help your teen feel better again.