Well for someone that supposedly was taking an antidepressant he has no idea how it works ...which makes me somewhat doubt he's taking them. It's quite common for people to be prescribed antidepressants and not take them because they have ulterior motives in having a medical record for depression ...(such as claiming a group of 7 individuals have destroyed their mental health & business).
Far from preventing serotonin uptake in your brain; as Lloyd said, SSRis work by making serotonin more available for sending messages between nerve cells. I also know from my own experience stopping them is no easy task if you genuinely need them. To casually do so in order to take a hallucinogenic - which are definitely associated with serious mental health issues like psychosis/schizophrenia - would be quite a scary prospect if you've experienced serious depression.
I don't know. Maybe I'm wrong but it all seems a bit off. You don't play with your mental health if you've ever experienced problems, or witnessed people you care for, do so, too.