I sometimes have horrible depression, and it leaves suddenly. It is like some gear is stuck in my brain, and everything starts piling up behind that stuck gear. Finally the pressure gets so great that the gear starts turning again, and the depression leaves instantly.

I only had one breakdown. I started feeling like things were strange a couple of days before it happened. People seemed to be acting strange, and I had an auditory hallucination. I hate flying, and I was also stressed about meeting a friend for a weekend. At the end of the weekend when I arrived home on the airplane, a passenger made a strange comment, and I suddenly saw the "explanation" for all that strangeness. I felt like a balloon that suddenly deflated. That is when I became extremely delusional. Luckily it only lasted a few weeks.

The lead-up to a breakdown is usually longer than two days. Sometimes it is months.