Is there a birth control which isn't lowered in effectiveness while taking other meds?

I am 16 and recently became sexually active. I am taking the pill now only to help regulate my hormones as I have PCOS. Along with the PCOS also comes the Metformin and an antidepressant. I must take those pills and I also take a vitamin D pill for a deficiency. Is there a form of birth control which won't be lowered in effectiveness while I'm taking these meds? Also, does anyone know if Metformin and the antidepressant lower the effectiveness?