You don't necessarily have to be depressed to take these supplements labeled as supplements for depression. These are supplements which may boost your mood, whether you're depressed or not. They're labeled supplements for depression because that's what they were studied for.
“You say you’re ‘depressed’ – all I see is resilience. You are allowed to feel messed up and inside out. It doesn’t mean you’re defective – it just means you’re human.” ― David Mitchell, Cloud Atlas