Ute, I appreciate your study into the effectiveness of meditation, but I must point out a major flaw that you haven’t addresses in this article. There are many different forms of mediation, with different techniques and different results. They cannot all be lumped together.
I’m a long-time practitioner of Transcendental Meditation, which is probably the most widely studied and scientifically scrutinised technique of meditation. Proponents of TM claim a lot of health and psychological benefits, many of which I’ve personally experienced, and most of which are backed up by numerous scientific studies. The same cannot be said about other meditation techniques like mindfulness, contemplation, etc. which don’t share many of the unique characteristics of TM, such as EEG coherence.
Here is an intro to some comparisons:
When looking into the effectiveness of mediation it’s extremely important to study and compare different forms of meditation and never lump everything called “meditation” together, as they can be completely different techniques with different effects on the physiology.