i saw something like this suggested in a post made like 2 years ago. so the concept i have for a depressed character trait would be that if you choose it your character suffers from periodic episodes of depression that last for 1-3 of weeks before they pass. they happen randomly maybe once in the span of 2 months. maybe they could be triggered by things that currently cause unhappiness if you let it go on for too long. if you have the trait and have an episode you wouldn't be able to get out of the "feeling a little sad" state regardless of what you do to increase happiness. Antidepressants can help reduce the time and severity of the depression. maybe it could go as far as not being able to get out of the higher levels of depression unless you take an antidepressant once a day. I could go on but i just wanted to get the general idea out