Effect of electroconvulsive therapy on gray matter volume in major depressive disorder

Although the clinical efficacy of electroconvulsive therapy (ECT) is well established, the underlying mechanisms of action remain elusive. The aim of this study was to elucidate structural changes of the brain following ECT in patients with major depressive disorder (MDD).

Fifteen patients with MDD underwent magnetic resonance imaging scanning before and after ECT. Their gray matter volumes were compared between pre- and post-ECT.

There were significant volume increases after ECT in the bilateral medial temporal cortices, inferior temporal cortices, and right anterior cingulate. Further, the increase ratio was correlated with the clinical improvement measured by the Hamilton Depression Rating scale.

All subjects were treated with antidepressants that could have a neurotoxic or neuroprotective effect on the brain.

We found that there were significant increases of gray matter volume in medial temporal lobes following ECT, suggesting that a neurotrophic effect of ECT could play a role in its therapeutic effect.