Way, way, back I woke up one morning clinically depressed... no problems going on in my life.. it was strictly brain chemistry getting screwed up. Went to bed a reasonably happy person and woke up like I was suffocating in a deep, dark, black hole. I'm still, mor than 45 years later, terrified of waking up that way again. Truly. It took a year on meds for the brain chemistry to correct and they don't know what causes it to happen in the first place... well, other than sleep patterns getting messed up.. but what causes that?! I think its putting the cart before the horse actually. I think it has to do with hormonesl but I'm not a doc. Anyway, I would never risk any med that messed with brain chemistry and Chantrix obviously does or depression wouldn't be a known side effect.