This first link is a VERY good site, it is neatly organized and filled with massive amounts of information, some of which i'm sure certain people in a certain government would rather you not know. This site has been very helpful to me over the past few years, if it didn't exist I'm sure some bad things would have happened to me by now. BUT, because it exists, certain precautions were researched and implemented allowing me to have had some of the most profound, awe-inspiring, spiritual learning experiences that i never could have imagined.
The Lycaeum is also another great drug information/research site. The LEDA search function works nicely, I still prefer Erowid's layout but for best results, use BOTH sites.
Between these two sites there are hundreds of links to other sites of a similar nature. Enjoy! And above all, be careful and know what you are doing.
HPPD (Hallucinogen Persisting Perception Disorder) is a complication that some users of hallucinogens experience. The intensity of the disorder can vary greatly. It is classified in the DSM-III and DSM-IV manuals (handbook for the American Psychiatric Assosiation) so it is recognized by medical professionals as a real disorder. To find out more you know what to do...click the pic! Also the link below is another site for HPPD so you can have two sources in case you want to cross-check information.
Tell me, have you been there?
"A tired mind become a shape shifter, everybody need a mood lifter, everybody need reverse polarity, everybody got mixed feelings about the function and the form, everyone got to deviate from the norm"
Rush-"Vital Signs" from Moving Pictures