it could be clinical depression. this kind of depression is what i struggle with, even in my happiest moments i am pretty sad as well. for me, it’s explained by a lifetime of neglect and abuse. but it’s been proved that chemical imbalances in the brain are a leading cause of depression. it could certainly be that, but it could be other things as well. depression is an extremely complex disease, it’s even been proven that people with depression have a smaller hippocampus, which is likely caused by stress hormones. depression can also make the smallest situations more likely to be emotionally charged for you. this could mean that things that seem happy, or seem simple, end up being very complex and emotional for you. this has to do with the amygdala, which is a part of the brain activated by high emotions. so, long story short, it could definitely be a chemical imbalance, but it’s likely much more complex than that. things like sleep, proper nutrients, exercise also play a huge part in depression, especially sleep. if you’re not getting enough sleep, that could be causing everything, as sleep is vital for mood regulation. in my personal opinion, i think depression also stems from a kind of existential dread. my best way to describe it is that we all are born with this ache in us. along the way, we find many things to soothe the ache, or make it go away for a while. things like love, drugs, sex, family, books, tv. whatever it is that makes us feel alive. but, it may not work forever. i’d recommend checking your sleep/eating/exercise habits. if those are all in line, maybe it’s time for you to try something new in your life to soothe the ache for a while. a new hobby, new interest, meeting new people. new things come with both anxiety and excitement!!