Can depersonalization and derealization begin after using marijuana?

There is no unequivocal answer to this question, because everything in this world is too relative. We are all different, and this or that surfactant can affect everyone in very different ways.  Besides, it depends on a whole chain of factors, such as the percentage of THC in the finished product, the grade, quantity, and, most importantly, the user PERSONALITY. The only thing you can talk about with absolute certainty is that medical hemp prescribed by a doctor cannot have any negative effects.