Acute neuroaxonal remodelling after electroconvulsive treatment in patients with major depressive disorder: A pilot study

• Neurofilament light chain is a novel blood marker of neuroaxonal integrity that has recently been introduced into clinical practice. • Neurofilament light chain is acutely increased in serum after electroconvulsive therapy. • Future studies should determine if these effects correspond to treatment response or cognitive impairment. Electroconvulsive therapy (ECT) is an effective treatment for major depressive disorder (MDD). Neurofilament light chain (NfL) is a novel blood marker of neuroaxonal integrity, which is altered in some psychiatric disorders including MDD. Prior studies reported no long-term impact of ECT on NfL levels, but the acute effects are unclear yet. Therefore, we investigated serum NfL levels from 19 single ECT sessions in 13 patients with MDD. We found an acute increase in NfL levels post-ECT (Cohen's d=0.45), suggesting transient cytoskeletal remodelling in axons. Further research is needed to ascertain if these transient changes correspond to treatment response or side effects such as cognitive impairment.