Pretreatment Symptom Provocation Does Not Improve Deep TMS Outcomes in OCD

Exposure therapy is not likely to affect the efficacy of deep transcranial magnetic stimulation (TMS) for obsessive-compulsive disorder (OCD), according to study results published in Journal of Obsessive-Compulsive and Related Disorders.

Patients (N=94; mean age, 38.8 [range, 22.2-68.0] years; 59% men; 83% White) with OCD were recruited at 11 study sites. Participants were randomly assigned in a 1:1 ratio to receive either active deep TMS or sham treatment. The deep TMS intervention was delivered in 20 Hz pluses at the foot motor cortex, and was administered daily for 5 weeks and 4 times during the sixth week. Before each treatment, a 3- to 5-minute symptom provocation intervention was performed in order to engage the neural circuits involved with each patient’s OCD symptoms. The primary outcome was the change in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores from baseline.

Among the study population, OCD onset occurred at a mean age of 13.1 (range, 4-30) years, and Y-BOCS score was 27.3 (SD, 4.0) points at baseline.

The provocation intervention consisted of both external and internal stimuli for 35% of patients and only internal stimuli for 65%. The mean Subjective Units of Distress Scale (SUDS) score during provocation was 6.0 (SD, 0.73) points.

The change in Y-BOCS score through week four was observed to have a significant intensity-by-time-by-treatment interaction.

Following subgroup analyses, no significant effect of distress was observed on treatment outcomes in either the sham (β, 0.21; P =.11) or active (β, -0.012; P =.92) groups.

Stratified by level of distress, no group-by-time interaction was observed for the effect of deep TMS on Y-BOCS score among individuals with a low-level of distress (β, -0.17; P =.35). Among those with greater distress, the group-by-time interaction trended towards significance (β, 0.34; P =.06).

Overall, Y-BOCS scores decreased from 29.29 points at baseline to 22.18 points at week 10 among the high-distress active recipients and from 26.80 points to 18.87 points among the low-distress active recipients. Y-BOCS scores decreased from 27.25 points to 23.64 points among the high-distress sham recipients and from 25.94 points to 20.33 points for the low-distress sham recipients.

The study may have been limited by the decision to customize the provocation protocols for each patient on the basis of their symptomology rather than using a standardized protocol.

Study authors conclude, “Results suggested that processes that are typically associated with treatment outcome during exposure therapy were not related to clinical improvement in a trial of symptom provocation plus deep TMS vs sham stimulation for adults with OCD. Future work should investigate the potential of exposure therapy combined with neurostimulation as an innovative, interdisciplinary way to enhance treatment outcomes.”

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.