Repetitive Triggered Somatosensory Discrimination as a Potential Treatment for Treatment Resistant Depression and Anxiety: A Pilot Study

Abstract

Background: Depression and anxiety are the most common mental disorders in Israel. Current pharmacological treatments are frequently insufficient in reducing symptoms, particularly for treatment resistant depression and anxiety. Considerable evidence has accumulated in clinical settings and research studies both with animals and humans that has implicated the involvement of the primary and secondary somatosensory and insular cortices with the regulation of emotions. Awareness deficits and irregularities of sensory experiences in the form of decreased interoceptive awareness and accuracy in both depression and anxiety have been linked to symptomology and symptom intensity which has this why this area should be a target for intervention. Nonetheless, there is a paucity of research on the effects of discriminatory somatosensory tactile stimulation on symptoms of depression and anxiety. The current pilot study aims to examine the efficacy and safety of the Repetitive Triggered Somatosensory Discrimination Device (RTSDD) in the treatment of depression and anxiety. Methods: The present open-label pilot study included 30 outpatients diagnosed with major depressive disorder according to the DSM-V. The Hamilton Depression Rating Scale-21 (HDRS-21), the Hamilton Anxiety Rating Scale (HAM-A) as well as the Vision Analog Scale (VAS) for anxiety and depression were used for the evaluation of the severity of symptoms. A specialized device was developed called the Repetitive Triggered Somatosensory Discrimination Device (RTSDD) was utilized that provides tactile vibratory signals to the skin, foot, hand or palm at varying intensities. The device was linked to a computer program that controlled the gradual increase of somatosensory discrimination during each of the total 8 sessions of treatment. Results: Out of 30 participants, 21 (70%) completed the trial. The mean general severity of depression (HDRS-21) was reduced from 19.48 (SD = 5.49) at baseline to 14.86 (SD = 8.29) at week 4 and to 12.67 (SD = 8.20) at week 8. The reductions were found to be statistically significant for all measurements (F (2,40) = 9.756, P < 0.001). The mean level of anxiety (HAM-A) was reduced from 26.09 (SD = 9.59) to 22.95 (SD = 12.55) at week 4 and to 19.19 (SD = 11.57) at the final stage (F (2,40) = 5.796, P = 0.006). The mean VAS Depression level was significantly reduced from 53.15 (SD = 24.52) at the beginning of each session to 43.84 (SD = 24.49) at the completion of each session (t (29) = 4.028, P < 0.001). The VAS Anxiety level was also subsequently significantly reduced from 53.62 to 42.47 (t (29) = 4.537, P < 0.001). Limitations: The study was an open-label design with no control or placebo group and a relatively small number of participants. Conclusions: The current study provides proof of concept for the use of the RTSDD in the treatment of depression and anxiety.