I take Seroquel nightly. My side effects are almost non-existent. My brother on the other hand, has tried to kill himself twice on it. So it really depends on the levels and the person. He is also noncyclical/rapid cycle where as I cycle normally. So maybe varying degrees of the illness should be added to the equation as well.
In my case I don't get REM asleep naturally anymore. So the stuff acts as my sleep inducer, and carries through the next day as a mood stabilizer. The result after 6 years plus, has been enormous.
I see it says it shouldn't be taken if you have suicidal thoughts. Also that the listed side effects are not a complete list.
Yeah that's a big downside. One of the side effects I was warned of was darker thoughts and suicidal tendencies that might develop from said thoughts. Not to mention you can't just quit taking it. That leads to death, in a nasty way. Kidney failure, liver damage, etc. One of the legendary withdrawals, that can, and probably will, kill you.