For me, it's been relative to other factors. Also, I have had very good periods somewhat quickly followed by bad ones, again. I must also mention that for me (and I think many) medications alone cannot be relied on. It's a combination of factors that have brought me longer-term mental wellness. If I combine all, it took a good 13 years after the beginning of my worst string of episodes.

I will not blame medications alone for the time consuming period mentioned above! That would be inaccurate and a cop out. Major changes needed to happen in my life for long-term stability. Mastery of coping and healthy living skills needed to be accomplished. I had to take responsibility for bad habits and change them. It was a personal journey, for sure, and one requiring patience and determination. Though others helped me along the way, it was up to me to do the work.