Absolute bullshit. To say there are no studies demonstrating better effectiveness than placebo is a tired old meme. It is true that SSRIs don’t have a profound effectiveness over placebo like some drugs.. but that does not make them useless. Current understanding is that they are effective, just not very much.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

This meta analysis has John Ionaddis as one of the coauthors (if you don’t know why this is interesting look it up).

Also nothing is easily “disproved” in medicine (or most science) so even if “neurotransmitter imbalance” is false, you’re still wrong nothing is on the way to being disproved. Furthermore, current understanding of SSRI effectiveness is not based on “correcting neurotransmitter imbalance”.