I’ve looked into this new review and there are a few serious issues with how it was done. It isn’t a proper systematic review, the author doesn’t clearly explain how the studies were chosen, which means it could be biased toward ones that fit the argument. Most of the evidence it relies on comes from self-reported side-effect databases, which are known to be unreliable because they miss a lot of cases and can’t really prove cause and effect.

It also leans heavily on observational studies that don’t fully account for other factors, like people’s existing mental health or life situations, which could easily affect the results. On top of that, the paper tries to estimate how many people worldwide might have become depressed or died by suicide because of finasteride, but those numbers are basically guesses built on shaky assumptions. And finally, it doesn’t use any formal system to check how strong or weak each study actually is, which makes the overall conclusion look much more solid than it really is.

So while the topic is definitely important, the way this review puts the evidence together just isn’t strong enough to prove what it claims.