Rapid cycling is when you have 4 or more cycles in a year. Some people cycle within a day called ultra-rapid, or ultra-ultra-rapid cycling. This is not a DSM category, however. Cycling can happen when medication is taken, it is called breakthrough. Few people have found a medication or medications that stop cycling altogether. I am on meds, and have ECT every 3 weeks and I still have mild depressions at times, usually during the week before ECT.