It's an amazing show with excellent insight. It is silly and lighthearted at times, and an emotional baseball bat to the face at others.
I've heard it can trigger depression.
I mean, it's not like a cursed video tape that kills you, but your mental state may fall a few notches. If you don't feel emotionally stable, bojack is not a good watch. Take breaks if you need. The later seasons get HEAVY.
I highly recommend it and also never plan to watch it again.