Repetitive transcranial magnetic stimulation (rTMS) on the left dorsolateral prefrontal cortex (DLPFC) is safe and efficient for treatment-resistant depression (TRD). More intensive rTMS protocols could improve clinical outcome.

We report on an intensive high frequency (HF)-rTMS treatment protocol in patients unresponsive to current treatment strategies.

Monitoring effectiveness and tolerability.

Patients were diagnosed with TRD, schizoaffective disorder, bipolar type or bipolar type I disorder, mixed episode. All were unresponsive to adequate therapy (rTMS excluded).HF-rTMS was administrated on the left DLPFC under MRI guidance. In each 20 Hz stimulation session, the patient received 40 trains of 1.9 seconds duration at 120% of the motor threshold. The 20 HF-rTMS sessions were spread over 4 days (5 times/day), yielding a total of 31,200 stimuli.

There were neither seizures nor important adverse events. The bipolar patient clinically responded (Hamilton Depression Rating Scale (HAMD) from 20 to 9) following treatment day 1. After completing the protocol a week earlier, the TRD patient's HAMD went from 28 to 5. There was a 5 point decrease in the score of the schizoaffective patient. He improved on the brief psychiatric rating subscales blunted affect and emotional withdrawal. No positive symptoms occurred. None of the patients had significant elevations in YMRS scores or in psychomotor activity.

‘Intensively’ targeting the left DLPFC was tolerated and safe. Our results suggest a strategy of HF-rTMS protocols in non-responders to classical treatment. Larger sham-controlled HF-rTMS studies should substantiate these recent findings.