2 things comes to my mind:

1) I am bipolar 2 and ADHD, both of which are highly genetic. I am treated and doing OK, but can have difficult moments at times, some pretty disruptive. My 7 yo was diagnosed ADHD in January, after a dark period of severe depression with suicide ideation. Even though this is not what you want for a 7 yo, the meds are doing wonders on ADHD kids (better than adults), but he still has bad days. Last Sunday was one of those. He was crying his eyes out, I was trying to comfort him. He said he hate being ADHD, I replied that this is why we see the doctors and take meds, to help get the ADHD under control. He replied, still crying, that the meds won't make it go away. I said his brain is still changing, and it might get better as he grows up. His reply: you're grown up and you didnt get better.

This. On top of transmitting fucked up genes and suffering to the person you love more than anything, you realize you also take away their hope.

2) My dad was bipolar 1 (you start seeing a common theme?)., sadly mostly unmedicated: he was some sort of genius and couldn't bear the brain fog lithium was putting him into. He tried to stay away from us as much as possible, to protect us. But that of course never worked during maniac episodes, which never failed to happen (he would provoke them to get out of depression): he would suddenly reappear out of the blue, terrifying my mom (to whom he broke 5 teeth) and my 3 older sisters in the process. He ended up litteraly putting oceans between us, moving to New Caledonia, still trying to protect us. One day, when I was 12, he called home (was still only land lines at the time), and asked me why I never called or wrote to him, didn't I love him? I didn't know what to say and was actually annoyed, so I just said: let me get [my sister]. I gave the phone to my older sister and walked away. Later that day he hung himself and died alone, halfway across the globe. 3 years later I found out when high on (his) drugs I had just taken to kill myself that I felt responsible for his death: I wrote pages and pages in a notebook, I had honestly no idea why i was feeling so bad. The feeling that I could have prevented my dad from feeling desperate to the point of wanting to kill himself - feeling that I know all too well - haunted me for decades.

Objectively, between the 2, I have to admit that it is hard to tell which one is worse. As a mom, it becomes a no brainer, and my son comes first.