Quote - "The fact that the process was actually planned by the artist and you are seeing the results on the internet shows that it's a gimmick."

This ^^

 

What does that have to do with whether or not he actually took the drugs?  It's not just that drugs affect cognitive function, they're more commonly taken for their mood altering properties.  I could do a series of self portraits while listening to various types of music and they would all likely reflect in some way the effect the music had on my mood at the time.  Contrived doesn't equal faked.