On the other side of the coin, Greg and Isabel are both addicts who happen to be taking the same drugs.
There’s also some telltale signs that hint at Bliss’s supposedly fabricated world is just that.
The larger key to Greg’s world being a reality is the fact that he looks to be abusing his meds, which include hallucinations and memory loss as side effects.
After Greg snorts his medication, his wallet glitches out a little, and the movie proper begins.