Lack of early reduction in depression severity predicts treatment non-response with 10 Hz and accelerated theta burst repetitive transcranial magnetic stimulation in treatment-resistant depression.

BACKGROUND

Accelerated forms of repetitive transcranial magnetic stimulation (rTMS) are proving to be a safe and effective for treatment-resistant depression (TRD). However, the likelihood of treatment response remains difficult to predict. It is possible to assess inadequate treatment responses early in treatment courses to predict eventual non-response by course end.

METHODS

Post-hoc analysis of prospective clinical trial data was conducted (N = 298). Participants were randomized to one of three treatment arms: daily, unilateral 10 Hz rTMS to the left dorsolateral prefrontal cortex or accelerated bilateral theta-burst stimulation (TBS) at either 80 % or 120 % resting motor threshold stimulation intensity. Clinical response was assessed using the Quick Inventory of Depressive Symptomatology (QIDS). Negative predictive values (NPVs) were generated at week 1 using various QIDS percentage improvement cut-offs to predict eventual non-response.

RESULTS

Participants who showed a ≤ 10 % or ≤ 20 % improvement in QIDS score by week 1 had NPVs ranging from 70.0 % to 97.5 %. Higher NPVs were found for participants randomized to low-intensity accelerated TBS than 10 Hz daily rTMS at week 1.

LIMITATIONS

Accelerated TBS and standard rTMS courses featured relatively short courses of 20 sessions. Analyses predict eventual treatment response using only change in QIDS severity without subscale analysis.

CONCLUSIONS

Early treatment non-response potentially has predictive utility, including in an accelerated TBS protocol. Further studies should determine whether there is clinical benefit in reviewing and/or adapting treatment protocols in view of these findings.