Emerging research shows that depression is linked to imbalances of bad bacteria in the gut microbiome, and not a serotonin chemical imbalance as previously thought.

When there's an overgrowth of bad bacteria in the gut, it causes inflammation in other parts of the body, including the brain. That can cause depression, anxiety, and other health problems. Inflammation also inhibits neurogenesis.

So it would be best to address your gut health before taking an antidepressant. Plus it's not a good idea to take antidepressants while recovering from a concussion because they don't help the brain heal and can make it worse.

Gut Health and Depression: What’s the Link?

Stop eating sugar, refined carbs, and fast food.
Eat more protein, veggies, and fiber
Take probiotics