I think mindfulness here is meant as a synonym for a particular type of meditation. This article is broadly correct from my perspective—we should approach meditation with some caution, because it is
not a well-defined self-therapy modality. It's quite possible, with the wrong practice instruction, to end up hurting yourself, or just getting nowhere.
Meditation—and even just mindfulness meditation—is a domain of practice as broad as "exercise."
If you are interested in engaging with this type of practice, I recommend working with a qualified teacher in a spiritual tradition. These practitioners will have extensive training (at least decades) and will be drawing from a few thousand years of careful study of the effects of meditation (as found in Buddhist and Yogic/Hindu documents and oral traditions).
For working on emotional issues without dedicating years to practice, therapeutic modalities developed in the West are faster, more reliable, and safer.
Meditation—and even just mindfulness meditation—is a domain of practice as broad as "exercise."
If you are interested in engaging with this type of practice, I recommend working with a qualified teacher in a spiritual tradition. These practitioners will have extensive training (at least decades) and will be drawing from a few thousand years of careful study of the effects of meditation (as found in Buddhist and Yogic/Hindu documents and oral traditions).
For working on emotional issues without dedicating years to practice, therapeutic modalities developed in the West are faster, more reliable, and safer.