This study investigated the impact of accelerated Transcranial Magnetic Stimulation (aTMS) compared to daily sessions on outcomes in depression patients. While traditional TMS protocols involved daily sessions 4/5 times per week, this can be inconvenient for patients, particularly those travelling long distances to a TMS clinic. Recent well-designed studies have demonstrated that multiple sessions per day (aTMS) can be as effective as daily TMS. It was expected that these findings would be replicated in a clinical setting and that aTMS would be just as effective at reducing symptoms of depression as daily TMS.

A retrospective chart review of 240 patients (126 males, mean age = 42.36, range = 16–86) was analysed using multiple regression. Patients were treated for unipolar depression over the left Dorsolateral Prefrontal Cortex (LDLPFC) using TMS protocols that have been shown to deliver equivalent outcomes (Blumberger et al, 2018).

The aTMS intensity variable (aTMSiv) was calculated by dividing total number of TMS sessions by number of days between the first and last session (minimum of five days for inclusion). Therefore, a patient who had 30 sessions over 15 days would have an aTMSiv of 2. The mean number of sessions delivered was 24.46 (SD = 8.01, Range = 7–45) and the mean days between first and last treatment was 35 (SD = 20.21 Range = 6–105).

The main outcome variable was percentage reduction of PHQ-9 scores from baseline (mean = 17.89) to treatment completion (mean = 10.76). The mean reduction in PHQ-9 was 40%. The independent variables (IVs) included: aTMSiv, PHQ-9 baseline score, number of sessions, age and sex.

Collectively the IVs predicted PHQ-9 reduction at a statistically significant level (F (5,234) =7.91, p = 6.70E-07, R2 = 0.14). Individual analysis of predictors revealed that aTMSiv did not significantly predict PHQ-9 reduction (F (1,238) = 0.05, p = 0.82, R2 = 0.0002). Only number of sessions significantly predicted PHQ-9 reduction in this model (t = 6.04, p = 5.88E-09).

As the aTMSiv did not predict the change in PHQ-9, this suggests the frequency at which TMS is delivered does not affect the outcome when treating depression. Thus, either daily sessions or aTMS can be utilised to best fit the schedule and lifestyle of the patient.