I have the worst headache! I don't get headaches so I might not really know what a horrible headache is but I'm dizzy and nauseous and it's hard to walk, all from a headache! And I've recently had a CAT scan so I know there's nothing wrong with my brain. I'm just in a lot of pain and I'm having trouble sleeping too. I've been on Brintellix for about 3 months.