What do you I mean by saying black tea is a hallucinogenic? I will write the facts down that I discovered as short as possible.
Black tea is an diamine oxidase inhibitor. If black tea is your primary drink, then your diamine oxidase could be low. What I mean by drink it primary, is the tea is drunk only. Black tea could be the only thing that you drink, with sometimes having some soda or juice.
When the diamine oxidase is reduced enough, the histamine levels will increase. With the increased level of histamine, your body becomes undermethylated. When you become undermethylated, you will have a drop in dopamine, serotonin, and other brain chemicals. With those decreased chemicals, you will then have delusions and hallucinations. It can be bad enough that you will see things that are not really there. The symptoms of drinking black tea will cause a diagnoses of schizophrenia.
Black tea is good tasty drink, but too much of anything will cause a problem. It is not known to me how much black tea is needed to cause schizophrenia. I have drank black tea my entire life, becoming diagnosed when I was 22 years old. Looking back on my life in the past, I have had symptoms of schizophrenia from age 16. I started drinking black tea, primarily, from as far back as age 5.