Formerly it was easy to find on Google, but I guess Corona "fortified" health information and the results are really bad right now because you cannot match the topic accurately.

I had no success, but suggestibility of illnesses and conditions is a huge topic in psychology. There were many induced cases of conditions that stopped when the "patients" stopped therapy.

There are many reasons why patients would accept such a false diagnosis. I don't believe this is the case here, though.

Therapists have a long history of creating entirely false memories in children, telling them that they were abused by satanists as a child! Teenagers often go through some depression-like episodes due to love interests or whatever, so telling them they're medically depressed is a much smaller leap than what came previously.