Although your able to keep up your grades, dont mean alot. Il give you a little advice i wish i knew before hand and wish i didn't have to learn the hard way. Whoever told you about brain abuse was not lying, and must of found out first hand or know somebody that did. Im 26 turning 27 soon now. I was abusing pot everyday since i was 13, i stopped 6 months ago, and it was hard, mentally.. I was taking shrooms and/or lsd once maybe twice a month since i was 18 up untill recently. And ecstasy once every month, or sometimes just weeks apart, since i was 19 untill recently. Although im able to keep up with work and consider myself halfway successful, i am fucked in the head, i know it, people around me know it, and i suffer every day. My life will never be normal or the same. I sometimes just wanna die. I know everybody is dfferent, but if i can change anything, it'd be me doing drugs, i would of never touched them not even pot. You might be able to avoid mental and emotional issues with very occasional use, but after 10-15 years of daily pot smoking on top of other drugs, trust me ull feel the effects and it ain't gonna be fun. Your still young, id stop completely, or cut out the psychs and occasionally smoke just pot. I had a crazy spirtual trip 6 months ago and haven't touched drugs since. And it all hit me at once. Weed gives me anxiety all of a sudden now. My mind cant handle shrooms or lsd or xtc anymore. I think way to much. I struggle daily, shit dont seem real, i look at my girlfriend and freak out, i hang with my kid and freak out, i think about death, i wonder if i even exist, i suffer from anxiety now, heart problems, lungs are cashed, feel overall slower, i got awful derealization/depersonalization, my thoughts are all outta wack, nothing seems real and life seems weird now, like who am i, idk, im depressed daily and its hard to be normal or happy, and thats about half of it, i didnt wanna give you my whole life story. I pretty much runied myself, though, thanks to drug abuse. Sorry to blab about me, but you wondered about brain damage. There ya go, theres my insight on that. Light up on the psychs specialy, or you will end up like me, if you take enough over the years, dont trick yourself cause your able to keep up at school/work. Your only 16, you have time to correct yourself, you havent did much damage, yet*.. But in 10-15 years theres a chance you could be like me and wish you never took drugs, when your dealing with the awful effects daily.. Good luck and stay in school.. Btw, drugs didn't affect me in work or school, pot anyways, everything was the same, work and grade wise, i just enjoyed being there a little more cause i was high, the grades stayed the same, and the same amount of work got done, for me anyways, i was always able to handle drugs, back then atleast.