I used to cycle in about 2 to 3 year intervals and what I called my "mood changes" were not as radical. Last 2 years I been going thru the rollercoaster couple of times a year... 2013 and 2014 were super duper bad. There was no normal balanced state of mind. It was daily/weekly/monthly - just horrible. Now I have been quite well for past 6 months again. Just hoping it will stay this way forever