That's right, it's all about the situation and timing on conversational level. Definitely not a universal solution or trick to get over bad feelings. Guess what I want to say is that seeing the comical on another level, almost like from an absurdist perspective, can help people to cope better long term. This applies to your suicidal example, it's not that you can laugh when having an episode but it's the act of doing it later that creates distance. And maybe if we can condition our brain to detach from these negative emotions we can get some extra breathing room when it's the hardest?