Effects of the continuous theta-burst stimulation on the levels of peripheral blood neuroplasticity biomarkers in people with obsessive-compulsive disorder: Findings from an open-label trial.

BACKGROUND

There are very few studies exploring neuroplasticity impairments and neurodegeneration processes in obsessive-compulsive disorder (OCD). Additionally, the peripheral blood levels of neuroplasticity biomarkers in individuals with OCD and their associations with treatment outcomes remain largely unexplored. This study sought to compare peripheral blood levels of biomarkers reflecting neuroplasticity and neurodegenerative processes between patients with OCD and healthy controls (HCs) and to determine whether accelerated continuous theta-burst stimulation (cTBS) influences the levels of these biomarkers in OCD.

METHODS

TThirty-three OCD patients participated in an open-label trial of cTBS. During the treatment, serum levels of 10 biomarkers of neuroplasticity and neurodegenerative processes were assessed at three-time points. Additionally, 42 HCs were enrolled.

RESULTS

The cTBS treatment was associated with significant improvements in OCD and depressive symptoms. Baseline levels of all biomarkers, except myeloperoxidase (MPO), were significantly lower in OCD patients compared to HCs after adjustment for covariates and multiple testing. The levels of platelet-derived growth factor-AA increased considerably following the cTBS treatment, but they remained significantly lower than in HCs at the follow-up. In turn, the levels of MPO significantly decreased during cTBS treatment and were substantially lower one month after the cTBS stimulations compared to HCs. A reduction in MPO levels was significantly and positively correlated with a reduction of OCD and depressive symptoms.

CONCLUSIONS

This study suggests that neuroplasticity biomarkers are reduced in patients with OCD. cTBS treatment is associated with symptom improvement, albeit with a limited impact on peripheral blood biomarkers reflecting neuroplasticity and neurodegenerative processes.