I had a mirena (different product but an implanted hormonal device) and that seemed to make my depression worse, when I had it removed my mood didn't bounce back as I hoped it might, my acne took about 9 months to clear up and the weight gain about a year.

Hormonal treatments and depression are a mixed bag, sometimes they work, other times not. With me progesterone (Implanon contains etonogestrel, a progesterone like hormone) definitely aggravate my depression. I think when female hormones can help is when they are in combination with an oestrogen, but I'm not sure. Oestrogen carries its own risks though and I personally wouldn't go there.

Has your cycle returned to normal or are you using another hormonal birth control instead? If your cycle has returned to normal and you are not using another hormonal birth control then it is probably time to see a doctor about your mood. If your cycle hasn't gone back to normal then give it another month or two, then see a doctor. If you are using another hormonal birth control then maybe this one doesn't suit you either, again talk to a doctor.

Hope this makes sense.