Good points by dollyn.
It is not unusual for people with ADHD to self medicate. Marijuana seems to be the drug of choice (probably cause it slows things down for them).
Your memory may not be going, its just that with ADHD its very hard to concentrate and memorize things. If you are still in school, its getting harder and harder which makes it even more difficult to memorize things. You have to start do all those little memory tricks. Main one is to break things down into small segments - that way you don't have to concentrate as long. Plan out your studies. Sing things, use powerpoint, voice recorders, self videos - anything to change it up and make it interesting.
Strattera does not have methamphetamine, and thus works in a different way. Although if you do really have ADHD, the methamphetamine will affect you very differently than a normal person (it will actually slow you down).
Only real way to find out if you have OCD is to see a good psyc. Probably would be a good idea just so you find out how to deal with ADHD besides self medicating . There is an OCD forum on this site that should also prove helpful.
Congratulations on starting to look for answers. The best way to help yourself is to get information. Good Luck!!!!
I am not a doctor but first you should stop the marijuana usage.
adderall and concerta can cause side effects, and if you go to stop them you need to ask your doctor how you should stop taken them,because if you stop taken them the wrong way you can cause more health problems to your self.
a lot of people on the street take these drugs because they are like speed to them and give them as rush.also if you stop taken them you should take any pills you wont be taken anymore to the doctors so they can get ride of them in the right way.
also look up the side effects to the medicine on drugs.com and it will show you what you need to know.always look up all the medicines that come into my home .