Depression that only lasts for a day or two is not worth the side effects of taking an anti-depressant. I would recommend trying to find other ways of dealing with these short periods.

I recently read that SSRI's reduce the amount of time the brain spends in REM sleep. Since REM sleep is when the brain does its healing, maximizing REM sleep should be a priority.

The normal clinical standard for depression is depression that lasts for weeks at a time.

You sound like you are just having the ups and downs of PCS, but then, it is still worth getting a professional opinion.