So, I was reading up (quickly) on what the research says about bipolar disorder in women. Most studies seem to say those transitions into perimenopause and then again into menopause seem to be a period when depressive symptoms increase. What I didn't find were many accounts of postmenopause (which is the stage I saw in my family friends with bipolar disorder). A great deal of research questioned what was really attributable to bipolar disorder and what was more a symptom of perimenopause/menopause. Saw several that said more research needed to be done -- duh. This article was interesting:

Menopause and Bipolar Disorder | PsychEducation