Here's what happens.
First, any given trip alleviates depression for about a month or two. That makes sense to me in a sense that the word "trip" isn't a coincidence-- a really fun intense vacation in a foreign country also alleviates depression for a month or two. You swear that when you come back things will be different, but then you have to answer slack messages at 9pm, and your project is slipping at work, and your wife is flirting with strangers every time you go to a bar, and well... in a month or two you're back to feeling exactly the same way you did before (until you take the next vacation).
Second, people who discover psychedelics go on a multiyear quest for enlightenment. They keep taking various drugs, keep feeling like they understand things better and better, get sucked into the psychedelic social vortex of other truth-seekers, and generally believe that their life is full of meaning and is going to turn around at any moment. Except by any objective measure they're still nervous wrecks-- they have every physiological symptom of stress and depression, and aside from temporary alleviation of their symptoms (see part one), they always regress to the mean.
Third, after a few years of this people eventually reach a fork. Most people realize that their psychonautic journey is at best leading them in circles, and at worst is causing their life to spiral down the drain. So they give it up, get a job without 9pm slack messages (or find a better way to adjust to stress), marry someone who isn't constantly on the verge of cheating, start doing regular exercise, and generally find a way to settle into a reasonably balanced life.
A small minority of people double down, grow out their (usually grey by then) hair down to their shoulders, go to festivals and workshops, talk of energy and chi and chakras, stare into the eyes of strangers, and touch each other's faces.
Generally speaking, I haven't run into anyone yet who found a third path. So, while I'd be the first to admit I'm wrong and celebrate if this proves to actually work, if I were a betting man I'd bet against at any reasonable odds and sleep secure in the knowledge that my money is safe.