I got an email asking about Bipolar Disorder (AKA Manic-Depressive Disorder) and how it related to the traditional maps of the Progress of Insight. As one who advocates for truth in advertising and frank disclosure of what can happen when people get into insight practice, both good and bad, here is my response in slightly edited form. I hope that it provokes some thoughtful discussion of this complex topic.
***************
You are obviously not the first to notice the similarity between A&P events and Manic Episodes and The Dark Night (Dukkha Ñanas, Insight stages 5-10) and Depressive Episodes. The parallels are many and striking.
Here's a short list:
Age of Onset: most people who cross the A&P spontaneously do so in their teenage years to 20's. Most people who are Bipolar will have their first Manic Episode then as well.
Sequence: The Dark Night follows the A&P like thunder follows lightening. Same for Depression following Manic Episodes.
Timing: The A&P tends to last some number of days to maybe a week or two tops: so do manic episodes. The Dark Nights that follows A&P Events tend to last for months: so do the depressive episodes that follow manic episodes.
Sleep: People tend to sleep very little during the A&P and be more tired during the Dark Night. Same for the corresponding bipolar states.
Energy: People tend to have all kinds of energy to put into grand projects, schemes, relationships, sex and the like during the A&P and have much less for those same things, including work, school and relationships during the Dark Night. Same goes for their bipolar equivalents.
Mood: People tend to be high as kites during the A&P and dark and depressed during the Dark Night. Same applies to bipolar states.
Powers: People in the A&P may feel they have special powers, common ones being things like seeing through their eye lids, seeing bright lights, reading other people's minds, traveling out of body, seeing past lives, hearing and seeing entities, and many others. Ditto for Manic Episodes.
Here are the differences:
People in the A&P tend to generally function well, where as people with Manic Episodes, as classically defined, tend to need to be institutionalized or medicated to avoid really destroying their lives, spending all their money, ruining their relationships, getting into fights, being arrested, gambling away all their money, having sex with lots of people, thinking they are the King/Queen of the Universe, etc. In short, this is a difference between functional hypomania and true psychotic mania.
People in the Dark Night tend to be somewhat less functional in terms of relationships and the like. In contrast, people with classic Depressive swings tend to be much more dysfunctional, suicidal, and may have psychotic features, like voices telling them to kill themselves, or delusions that they are very sick and will die soon, or everyone is out to get them, etc.
However, while I make the line clear cut by way of rhetoric, in truth it is not so straightforward. Case in point: I remember getting a call some time ago from someone who may actually be somewhere in the middle paths. They were suicidal at the time and quite afraid. A few days later they left Re-Observation and got in Equanimity and suddenly were fine, but it just goes to show that it is not always easy straightening this out, mapping it in real-time, or compensating even when you know the maps very well and are a skilled insight practitioner.
Another friend was in the middle paths and was formally diagnosed (rightly or wrongly) as having Bipolar II Rapid Cycling and put on meds for it, which helped somewhat. When they attained to a higher path they were suddenly alright and didn't needs meds at all. Was their diagnosis simply the struggling of a Western therapist to put the cycles of insight into their only related box, or was this actually a correct diagnosis that was in fact cured by more insight? These terminological questions are not just semantics and have real implications for mental health and insight practice and handling both skillfully. I wish I had firm answers to them, but I don't.
Regarding your question on whether or not the traditional sources help: I know of no Buddhist writings that address this. Nowhere have I found anything that describes these things in a way that fits with a Western psychological perspective. The traditional maps were written for monks, who in theory were pretty high functioning people, in a culture that had nothing like our current concepts of mental illness.
More interesting parallels: those who keep crossing the A&P and getting into Dark Night territory and then fall back due to not getting stream entry and then crossing the A&P again and getting into the Dark Night, etc., tend to get more reactive with each pass, just as people with Bipolar do: as they get older and have more manic episodes, they get worse.
If you are only having these experiences on retreat, they are probably related to the cycles of insight. Good practice and clear investigation with awareness of the maps and a willingness to compensate and keep your mouth shut except when around people who can help you navigate the territory is generally recommended. On the other hand, those who have these things in daily life with the features that seem more ominous of more classic Bipolar disorder should seek help quickly, as Bipolar disorder can really screw up your life. I have had a few close friends over the years who were Bipolar and I have seen what happens when it is not managed well and it is not pretty.
Where one might be tempted to argue that people with Bipolar Disorder are merely the far extreme of what can happen in the cycles of insight, I don't have sufficient evidence to support that and would need further confirmation, such as sufficient numbers of clearly Bipolar people gaining sufficient paths and suddenly being cured to make definitive conclusions. At this time, so far as I know, there is simply not enough data. However, as you point out, there certainly are so many parallels that it is hard to simply write them off as being unrelated phenomena.
It is not accidental that I sometimes refer to those who have crossed the A&P at least once as having "Insight Disease".