I remember the first time I smoked marijuana after schizophrenia, and I was floored.
The character of the experience had completely changed.
None of the usual characteristics of getting high were there. The ease of thought, euphoria, and general sense of relaxation had all transformed somehow.
Now there was a setting and a context to the experience. Hallucinations that were already present, intensified, and became easier to engage.
This may be difficult to relay, but hallucinations are not always easy to immerse and engage with. A comparison would be dreaming. Sometimes, if you continually wake throughout the night, dreams can fleet and depart, so that you never lose yourself completely.
But in a very deep sleep, dreams become fully immersive, so much so that you get lost in them completely.
But with marijuana, that fleeting sense to hallucination, would almost disappear completely, so that the experience became much more immersive and engaging.
I also noticed, that the next day after smoking, the intensity of hallucinations decreased and faded into the background, to a lower point to where they were before smoking, the night before.
If I smoked again the second day, the effect would be lessened, and the hallucinations would intensify very little or none at all.
The only other experiences I’ve had that intensified hallucinations were fasting and sleep deprivation. Except with fasting there was a greater clarity to the experience that came with it, and with sleep deprivation, a greater fear that I would lose my sense of reality completely.