Sorry to hear that you have been struggling with depression for 15 years. Depression certainly is a very complex issue and hard to deal with. I believe it is curable if working out with the right therapist or counselor.

Father, I pray that You will cast out all of the spirits of fear, all of the spirits of worry, and all of the spirits of anxiety that are influencing this dear one. Give him/her strength and courage to face each day, and rule his/her heart with Your love and peace. In Jesus’ name I pray, Amen.