I have searched twice since last July and found nothing about interactions with SSRIs.

Here is an example:
http://chronicfatigue.about.com/od/s...p/theanine.htm

I was having alot of anxiety during the night, bad dreams etc.

I started at 150mg at night and raised to 300mg after 2 weeks.
It really seems to help and even lowered my fasting glucose a bit which tends to run high. So that is when I searched again, and found the cortisol blocking action. Cortisol when released during stress has a very hours long negative effect on the brain.

I intend to stay on it still. I like it alot. It evens me out.
My son tested high in anxiety when he had his ADHD intake.
He started theanine months before I started. He likes it too.

Doctor's Best .... that is the one I'd recommend if anyone tries it.

Theanine and neuroprotective effects:
http://www.ncbi.nlm.nih.gov/pubmed/18452993

This is the closest I could come to Prozac:
http://www.livestrong.com/article/47...ase-serotonin/

Since theanine is mostly working on norepi, and dopamine, I could not find concrete effects with Prozac (SSRI).
Theanine does not appear on drugchecker at Drugs.com

So the bottom line is discuss with your doctor.
Theanine is found in green tea, and black tea.