ADHD is a fake illness and you should know this for your own benefit. Doing drugs is bad for your physical, and Spiritual health. It will only slow you down in the end, and possibly ruin your Spiritual life as a Satanist.
Use void meditation in place of Marijuana. This will work far better in the long run than drugs.
http://www.dailystormer.com/jewish-inventor-of-adhd-admits-its-a-hoax/
It's not the best article, but it's what I could find offhand. They claimed I had ADHD as well when I was a child. It's utter junk, and has been debunked.
I used to have racing thoughts, and my thoughts would jump from one to another or get jumbled. I no longer have any of this thanks to Satan helping me, and void meditation.
Here's some more information about the fictitious ADHD.
http://josministries.prophpbb.com/topic161.html
We Spiritual Satanists do not encourage drug use, we frown on it. You should to. It may be difficult in the beginning but things will get better in time.
Stay strong.
Hail Satan.