CNS Spectrums

Original Research

Augmentative transcranial direct current stimulation (tDCS) in poor responder depressed patients: a follow-up study

Bernardo Dell'Ossoa1 c1, Cristina Dobreaa1, Chiara Aricia1, Beatrice Benattia1, Roberta Ferruccia2, Maurizio Vergaria2, Alberto Prioria2 and A. Carlo Altamuraa1

a1 Department of Psychiatry, University of Milan, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy

a2 Center of Neurostimulation, University of Milan, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy


Objectives Transcranial direct current stimulation (tDCS) is a non-invasive neurostimulation technique that has received increasing interest in the area of mood disorders over the last several years. While acute, double-blind, sham-controlled studies have already reported positive findings in terms of efficacy and safety for tDCS, follow-up data are lacking. This need prompted the present follow-up study, which assesses post-acute effects of tDCS (no maintenance stimulation was performed), in the mid-term, in a sample of major depressives.

Methods After completing an acute, open trial of tDCS, 23 outpatients with either major depressive disorder or bipolar disorder entered a naturalistic follow-up (T1) with clinical evaluations at one week (T2), 1 month (T3), and 3 months (T4). A quantitative analysis of Hamilton Depression Rating Scale (HAM-D), Montgomery–Asberg Depression Rating Scale (MADRS), and Young Mania Rating Scale (YMRS) total scores, through repeated measures analysis of variance (ANOVA) (T1–T4) and paired t-test for comparing specific time points (T1–T2, T2–T3, and T3–T4), was performed. In addition, a qualitative analysis on the basis of treatment response and remission (HAM-D) was performed.

Results Even though a progressive reduction of follow-up completers was observed from T2 to T4 (95.6% at T2, 65.2% at T3, and 47.8% at T4), the antidepressant effects of acute tDCS persisted over 3 months in almost half of the sample. Of note, no post-acute side effects emerged during the follow-up observation. The most frequent causes of drop-out from this study included major modifications in therapeutic regimen (30%) and poor adherence to follow-up visits (17%).

Conclusions In this mid-term, open, follow-up study, tDCS showed mixed results. Further controlled studies are urgently needed to assess its effects beyond the acute phase.

(Received March 13 2013)

(Accepted June 19 2013)

(Online publication August 20 2013)

Key words

  • Bipolar disorder;
  • follow-up observation;
  • major depressive disorder;
  • poor response;
  • transcranial direct current stimulation (tDCS)


c1 Address for correspondence: Dr. Bernardo Dell'Osso, MD, Assistant Professor of Psychiatry, Department of Psychiatry, University of Milan; Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milano, Italy. (Email


  The authors thank Dr. Filippo Castellano, MD, and Dr. Massimiliano Buoli, MD, for their support.