Only just. 100-200 mg is a small dose giving gentle effects, probably around first plateau. Check out Erowid for DXM info at

http://www.erowid.org/chemicals/dxm/dxm.shtml

I would watch that nasty stuff though. With such frequent use you are most likely causing long term changes in your brain. Read the articles on impaired intelligence and olney's lesions (essentially holes in your brain).

Is it really worth giving yourself permanent brain damage thanks to not being able to find alternative kicks? Your young-you're gonna need your brain, or whatsleft of it.

Alcohol in moderation, weed and psychedelics are pretty harmless-I'd stick to them. For all my preaching though I might be able try some ketamine with a uni friend, something I've always wanted to try.