Why does this happen? Have you heard of it?

At night a few times this week, I will get bouts of depression but they last less than 2 minutes. Sometimes I get more than one bout of depression but it’s less serious, the extremely depressed bouts last less than 2 minutes. The less serious bouts of depression happens multiple times but is much more comfortable. Not sure why it happens, what are your thoughts about it? Like any literature on why you would suddenly become depressed for 30 seconds and than immediately go back to normal?

Why does this happen? Have you heard of it?
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