When I first started taking L-Theanine I felt better, my depression lifted notably in the first week alongside improvements in focus and motivation. I also noticed a substantial increase in energy, my mood was a little bit edgier in the morning than before, and my heartrate was much higher during workouts I had been doing for months (timed interval training). At first I thought placebo or that's just how I respond to it, but later the next week I read some user reported accounts that L-Theanine can potentiate amphetamines.

I had been taking 200mg of Suntheanine in the morning with my 50mg of Vyvanse on an empty stomach with water and decided to drop down to 100mg. I wasn't as edgy and my heart was no longer trying to explode.

To be honest I'm still somewhat bored with the things in my life, but there are far more likely causes for that right now, though the Vyvanse is most likely contributing.