Symptom provocation to enhance the treatment effect of transcranial magnetic stimulation for obsessive compulsive disorder—A systematic review, evaluation and discussion

Abstract

Obsessive-compulsive disorder (OCD) is a widespread neuropsychiatric disorder with a lifetime prevalence of 2–3 %. This disorder is marked by significant obsessive distress, leading to interpersonal and occupational challenges, as well as high economic and societal burdens. As 40–60 % of patients fail to respond to standard psychological and pharmacological interventions, there is a critical need for effective alternatives. Transcranial Magnetic Stimulation (TMS), a non-invasive procedure for focal cortical neuro-modulation, received approval by the Food and Drug Administration in 2018 for the treatment of OCD. The TMS protocol includes a step of symptom provocation prior to each treatment session, which is intended to increase patients’ responsiveness to magnetic stimulation. However, the absence of a standard protocol has led to significant heterogeneity in how symptom provocation is conducted, posing challenges in comparing studies. This paper systematically reviews the literature on the theories, methods, and parameters of symptom provocation, focusing on how it is implemented in existing clinical studies. The findings reveal a substantial lack of details in most studies about the execution and parameters of symptom provocation. There is a pressing need for randomized clinical trials to determine the optimal level of obsessive distress to be induced before TMS. The insights gained will inform future protocols and guidelines, enhancing the efficiency and precision of the symptom provocation procedure.