The main finding of this pilot study was a significant reduction in the TQ score (baseline vs. week 9) after thirty hours of this new manualized group therapy compared to the waiting list control group. Very recently, first results were presented from a randomized controlled study investigating mindfulness-based therapy in tinnitus patients . Notably, in this previous study neither mindfulness-based therapy nor relaxation training as a control condition exerted an immediate effect on tinnitus symptoms. This might at least in part be due to the large effect already yielded by the preceding psycho-education . However, during the follow-up period mindfulness-based treatment was superior to relaxation therapy .
In contrast to this previous study , progress tended to stagnate in our study. Clearly, mindfulness-based therapy depends on practice behavior . Thus, the retrogressive effects in our study point to a reduced training maintenance at follow-up and may indicate the relevance of boosting sessions for stabilizing treatment effects.
A pronounced long-lasting effect was also observed in a randomized, controlled study treating chronic tinnitus with a training program lasting five weeks with Qigong . Notably, Qigong had been trained in sessions of 2 hours weekly and one could question the time schedule of two weekends of intensive training of up to 11 hours in our study. Possibly a longer-lasting and repetitive training process would enhance longer-lasting effects through better incorporation of the exercises into daily routine.
Mindfulness-based therapeutic approaches have demonstrated beneficial effects in other stress-related disorders such as chronic pain [13, 29] or anxiety . With effect sizes of 0.37 for pain scores  and between 0.24 to 0.47 on anxiety scores in patients with chronic medical diseases , the effects of mindfulness-based therapies were smaller in those studies when compared to the effect size of 0.80 in our study. However caution is warranted in such comparisons, since further data from larger samples will be needed before the effect size of mindfulness- and body-psychotherapy based treatment in tinnitus can be reliably estimated.
Future studies should also address the specific relevance of the different therapeutic components and their potential neurobiological mechanisms. A significant increase in alpha power through meditation has been revealed by electroencephalographic  and magnetencephalographic  studies. Alpha power in sensory areas is considered an indicator of inhibitory function  and an increase of alpha activity by neurobiofeedback or transcranial magnetic stimulation has been shown to result in reduced tinnitus perception [33, 34]. Thus it is tempting to speculate that the beneficial effects of mindfulness- and meditation- based therapy may be mediated by an increase in alpha power. Moreover, brain areas which are known to be involved in tinnitus such as the left hippocampus , the posterior cingulate cortex , the temporo-parietal junction , and the cerebellum  have recently been shown to be altered by mindfulness meditation .
From a psychological point of view, few studies have focused on the potential mechanisms of mindfulness and acceptance-based training procedures in tinnitus patients, unfortunately. It has been proposed that mindfulness based therapy can facilitate adaptive responses by enhancing cognitive defusion strategies and symptom acceptance connected with a non-evaluative observation of internal events. For example, in a sample of 19 tinnitus patients the frequency of cognitive defusion behaviors and peak level of cognitive defusion as well as peak level of acceptance rated in session 2, predicted a symptom reduction 6 months following treatment, indicating that clients’ in-session acceptance and cognitive defusion behaviors appear to play an important role in the reduction of the negative impact of tinnitus .