There has been a bit of fuss recently about the possible “side effects” of mindfulness cognitive therapy recently (see the guardian for example). some people have written also about how it can be used to help pupils in school. I cannot speak as an expert in such things. Indeed one of the problems seems to be non-qualified teachers leading such groups and the participants experiencing some worrying “side effects”.
I think from a Buddhist perspective, the problem is best overcome by researching the lineage of your teacher: who taught them? and who taught their teachers? Read here, for instance, the life and practice of the Abbot of Samye Ling Monastery in Scotland, Lama Yeshe . If you are taught by by him or indeed by one of his students , you know you are in safe hands.
But there is something else. Meditation isn’t like a 28 day course of pills you get from your GP. It is a lifelong practice. There will be bad times and there will be hard times. It is probably best therefore to stick with your path once you have found it and not cherry pick from others. Its not a question of your way is better than his or hers, but that your way is the best FOR YOU.
The purpose of meditation isn’t to change you. You shouldn’t go into it wanting to get rid of this bad person you think presently are. As Pema Chodron writes “The problem is that the desire to change is fundamentally a form of aggression toward yourself” (The Wisdom of no Escape) Instead of trying to repress aspects of our self we should try to let them go and not act them out. There is is Trungpa Rinpoche (who was Pema Chodron’s principle teacher) quote I really like “The whole idea of meditation is to develop an entirely different way of dealing with things, where you have no purpose at all. In fact, meditation is dealing with the question of whether or not there is a such thing as ‘purpose.’
And so maybe it is better to know your teacher well and to be prepared for the long haul if you wish to get the most out of your meditation.