Hypnosis in asthma treatment

I am a health psychologist in training studying the use of hypnosis in asthma for my doctorate. My GP put me on to hypnosis and autogenic training to help my own asthma control, so I know about its benefits on a personal basis.

Is anyone aware of any studies being done with hypnosis or relaxation with visualisations in your area? Or if you find hypnosis useful as a treatment or adherence aid? Maybe you are interested in trying this out?

I'd be very glad of any pointers in the right direction.

Paul