Lateralized hippocampal volume increase following high-frequency left prefrontal repetitive transcranial magnetic stimulation in patients with major depression

Psychiatry Clin Neurosci. 2017 Nov;71(11):747-758. doi: 10.1111/pcn.12547. Epub 2017 Jul 31.


Aim: Repetitive transcranial magnetic stimulation (rTMS) has been applied as a treatment for patients with treatment-resistant depression in recent years, and a large body of evidence has demonstrated its therapeutic efficacy through stimulating neuronal plasticity. The aim of this study was to investigate structural alterations in the hippocampus (HIPP) and amygdala (AM) following conventional rTMS in patients with depression.

Methods: Twenty-eight patients with depression underwent 10 daily 20-Hz left prefrontal rTMS over 2 weeks. The left dorsolateral prefrontal cortex (DLPFC) was identified using magnetic resonance imaging-guided neuronavigation prior to stimulation. Magnetic resonance imaging scans were obtained at baseline and after the completion of rTMS sessions. The therapeutic effects of rTMS were evaluated with the 17-item Hamilton Depression Rating Scale (HAM-D17 ), and the volumes of the HIPP and AM were measured by a manual tracing method.

Results: Statistical analyses revealed a significant volume increase in the left HIPP (+3.4%) after rTMS but no significant volume change in the AM. No correlation was found between the left HIPP volume increase and clinical improvement, as measured by the HAM-D17 .

Conclusion: The present study demonstrated that conventional left prefrontal rTMS increases the HIPP volume in the stimulated side, indicating a remote neuroplastic effect through the cingulum bundle.

Keywords: hippocampus; major depression; neuroplasticity; repetitive transcranial magnetic stimulation; structural magnetic resonance imaging.

Publication types

  • Clinical Trial

MeSH terms

  • Amygdala / pathology*
  • Depressive Disorder, Major / therapy*
  • Female
  • Hippocampus / pathology*
  • Humans
  • Hypertrophy / pathology
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neuroimaging
  • Prefrontal Cortex / physiology*
  • Transcranial Magnetic Stimulation / adverse effects*
  • Treatment Outcome