It's hard to say with absolute certainty. There certainly is a lot of evidence scattered around both sides. Thing is, and I think a lot of the older ones among us can testify to it, is that back in the day, things were so much more in the closet, swept under the rug and simply not talked about. Problems, and people too, simply did not exist, if anything was "embarassing". It's sad really. Or, at best, things were couched in more palatable expressions. This struck me particularly in the case of my paternal grandmother. It had always been put as, "she drank herself to death". I don't know if the people who said it really believed that, or just couldn't bring themselves to see or say what it really was. One day, it struck me that something was amiss. She really wasn't even a drinker. I do know that she had become completely despondant and did not want to go on (my dad, her son, told me how very hard he tried to convince her to want to live). She stopped eating. And took up drinking. Big time. Here's where I get speculative about why she went about it this way. She was a staunch old-school Irish Catholic. Any overt method would undoubtedly have seemed too sinful to her. I just think she just didn't know what else to do. So I'm calling a spade a spade. It was suicide.

Probably the most obvious answer would be my mother. No dx (unthinkable!), but saw all the evidence first hand growing up. Very indicative of BP. (Additionally, she has become a horrific hoarder.) Even years later, my sister tried to broach the topic with my grandfather (not my biological one, he'd died of alcoholism), because we all lived in the same house. She was shut down immediately. They knew she had something seriously wrong, yet despite the havoc it had caused us as kids, they had never intervened, nor would talk about it at all. Ever.

So, long and short, it's a lot of clue gathering in the closets, but it sure didn't come out of nowhere.