I have practiced Buddhist meditation for over 20 years and am certified to teach mindfulness practices and for 10 years have taught both Buddhist meditation and mindfulness practices.

I agree that meditation practice can be very unhelpful to many people. Yes, I believe it can cause dissociation. I don't think it promotes the development of strong ego boundaries. In fact, just the opposite. So it can have detrimental consequences not just during meditation, but in relationships, work, etc., if a person has weak ego boundaries to start.

On the other hand, mindfulness practice is based on being aware of one's thoughts, emotions, environment etc. It can be very grounding. It is not the same as meditation.

Meditation practice, and mindfulness meditation practice are two very different things, and each has a different focus.

Too many people (including therapists) teach this stuff when they themselves are not really educated in these practices.

A meditation practice is actually quite difficult and one should not really be doing it without the guidance of a certified teacher.

Mindfulness is softer and more generic. A practice such as "eating an orange mindfully" is just an exercise to keep one centered and grounded, and I think it has clear and positive potential as a mental health tool. It should not cause dissociation. In fact, it could possibly help one to not dissociate. One can mindfully focus on the sounds in the environment, or on touch (such as when petting one's dog) -- and a good mindfulness practice to help with panic is to splash cold water on one's face, hold an ice cube, or slowly drink a glass of cold water. Mindfulness is like an anchor in the reality of one's sensations and experience.

The quote someone said above about mindfulness opening a door...should really be a quote about meditation. Meditation can stir up a lot of unconscious material. This is why it should not be attempted without the guidance of a certified teacher. It also might bring stuff up that should be dealt with by a therapist, and not a meditation instructor.

Mindfulness, however, should never do that. The purpose of mindfulness practice is just to...more fully appreciate the moment and one's experience.

Hope this helps.