Can Mirena Coil Cause Weight Gain And Mood Swing?

I had the Coild fitted a year ago, and put on 6kg, and the family have said my moods have changed somewhat. Without looking for anything to blame but myself for this, I have read that this could be down to the coil. My sister has the coil fitted too but has not had any of these problems. Can the Mirena Coil cause weight gain and mood change?