I am happy to see another article in which the writer warns against the overselling of mindfulness, and mentions that, because of possible negative side effects, mindfulness practices may not be appropriate for all. This article also warns that some people teaching mindfulness practices may not be qualified to do so.
Excerpts from "New voices: Are we mindful of how we talk about mindfulness?" (The Psychologist of The British Psychological Society):
Recently an emerging area of research led by Willoughby Britton at Brown University has suggested that mindfulness practice may not be appropriate for all. Whilst scientific research has not yet uncovered many negative side-effects from meditation, there are texts hundreds of years old that do touch on negative experiences or the ‘dark knight of the soul’ (see tinyurl.com/jw4swbk), suggesting there are hardships in contemplative practices. Interestingly, whilst in medical studies side-effects would always be considered in RCTs, they have often been neglected in psychotherapy research (Dimidjian & Hollon, 2010), and thus far, in meditation research. We remain largely unaware of evidence on participants who may be more vulnerable to undertaking meditation practices or those who may experience negative emotions, paranoia, confusion or a loss of identity – some of the experiences reported in Britton’s early research. This can of course all be a natural part of the meditative process, but, for some, such negative experiences can be heightened to an extent they can become very unwell. So there needs to be an awareness of undertaking mindfulness practices with a suitable level of insight and readiness to start meditation. Meditation may look and sound simple, but mindfulness practice involves a considerable amount of active effort – it is quite a commitment to achieve and maintain the benefits reported above. ...
Although there are not currently any formally recognised qualifications to teach mindfulness, and training pathways are not yet accredited, we must not forget that those teaching mindfulness should at the very least have their own established personal practice of mindfulness. Attendance at an eight-week course would not be sufficient for beginning to teach mindfulness techniques to others. We must encourage clients to seek teachers who have an established mindfulness practice, are appropriately trained and supervised and are following UK mindfulness teacher guidelines (Kuyken et al., 2012) to ensure continuation of credible and evidence-based courses.