This is a decent article but the author unfortunately has no understanding of what is known as a "spiritual emergence", which PKD very clearly went through and is critical to understanding his life and legacy. One of the first phases of this process is "anamnesis", in which you recall information from what is thought to be past lives. Laugh all you want, until this has happened to you, you can't even imagine what it is like, but PKDs entire experience with the fish symbol was a clear example of this. There are many other signs, his precognition, the "AI voice", etc., all of which are common.

These events can mimic psychosis and other mental illnesses, but they are anything but. They signal the start of an inner metamorphosis, likely biochemically driven, though we don't yet know the biomarkers. It's like a second puberty, you have all these weird urges to meditate and whatnot, and if you do it right you grow and come out the other side a different person with a different experience of the world than the pre-pubescent .

Because of the general cultural lack of understanding and guidance, PKD, while brilliant, could only guess as to what was happening to him and had no idea what to do about it. In other times and other cultures, perhaps he could have been guided through the process, just as parents guide their children through puberty. It can take years to unfold and can easily go off the rails, see: Gopi Krishna, Living With Kundalini.

Unfortunately substances are one of the things that can make it go off the rails, and his propensity for them may have contributed to his untimely death instead of the preferred outcome of an "enlightened" individual. Again laugh all you want, until we figure out consciousness we have no basis to assume the non-existence of higher consciousness. But granted this whole space is polluted with new age crap, so unless you've had this happen to you it's understandable to paint it all with the same brush.

His Exegesis is a wonderful work, one of his best. Highly recommend reading.