Your linked paper talks about how the "adult mammalian brain can produce new neurons". That isn't controversial. What used to be controversial, but isn't anymore, is that adult humans brains don't produce new neurons. Not in the dentate gyrus, not in the entorhinal cortex between the hippocampus and cortex, not even in the olfactory bulb. Your linked paper does not have any human studies of neurogenesis, only BDNF serum levels and
assumptions about what that means from mouse models. But mouse, even ape models, don't translate re: neurogenesis.
Like everyone else, yourself included, I used to think that THC's main anti-depressant effect was mediated through increasing survival of new neurons during their granual cell to neuron journey in the dentate. But nope.
Adult humans don't have new neurons.