The volunteers were split into two groups for the study which lasted two years and two hay fever seasons.
The first group with hay fever were taught and asked to regularly practice hypnosis as well as taking their normal allergy medicine.
The second group were monitored on the same basis as the first but without the hypnotherapy aspect of treatment.
After a year the researchers found that the volunteers who had been using self hypnosis had reported fewer hay fever symptoms than those volunteers who had only been taking regular allergy medication without the additional hypnosis.
During the second year, group two were taught how to use hypnosis and they were asked to implement the technique on a frequent basis as well as taking their allergy medication. At the end of the second year, these volunteers had also reported an improvement in their hay fever symptoms.