Transcranial direct current stimulation in patients with treatment-resistant major depressive episode

Background: Treatment-resistant Depression is defined as the failure to respond to two consecutive trials of antidepressants belonging to different pharmacological classes for appropriate periods and dosages in compliant subjects [1]. In this condition, both pharmacological and neuromodulation add-on strategies can be used [2]. S342 P.2.a. Affective disorders and antidepressants − Affective disorders (clinical) Transcranial Direct Current Stimulation (tDCS) is one of the latter techniques. It is safe and non invasive and it consists of the application of two electrodes (5 cm×7 cm) on the dorsolateral prefrontal region (DLPC). Anodal electrode is generally placed on the left DLPC and cathode electrode on the controlateral area. The current applied goes from anode to cathode at an intensity of 2 mA. This implies focal modulation of neuronal excitability, in particular anode determines depolarization, increasing thus neuronal excitability, while cathode determines hyperpolarization [3]. The purpose of this study was to assess the efficacy of tDCS in patients with an acute depressive episode, in augmentation with pharmacotherapy in drug-resistant depressed patients. Materials and Methods: 23 outpatients (M = 8, F = 15, mean age = 51.22±13.29 years) with a diagnosis of moderate to severe Major Depressive Episode [Hamilton Depression Rating Scale (HAM-D) 18] in Major Depressive Disorder (n = 15) or Bipolar Disorder (n = 8; of which n = 2 with type I Bipolar Disorder and n = 6 with type II Bipolar Disorder), according to the DSM IVTR, were selected after a clinical interview. All patients were requested to maintain their medications for one month without having shown any clinical response. Drug therapy had also to be maintained unchanged throughout the study. tDCS was administered for 5 consecutive days, 2 sessions per day (4 hours between the 2 applications). Each session lasted 20 minutes. Eventual changes of depressive symptoms were assessed by ANOVA for repeated measures with the following psychopathological scales: HAM-D 21 items total scores, melancholic items of HAM-D scores and Montgomery-Asberg Depression Rating Scale (MADRS) at baseline (T0), at the end of treatment (T1) and one week after the end of treatment (T2). Results: It was shown a significant reduction in mean total score of HAM-D from 19.83±5.71 to 13±7.62 (F = 16.59, p = 0.00), of MADRS from 24.35±7.09 to 16.7±10.18 (F = 16.19, p = 0.00) and of HAM-D melancholic items (MEL) from 11.83±2.83 to 7.48± 4.54 (F = 19.18, p = 0.00). This reduction was greater from T0 to T1 than from T1 to T2 (Paired t-test: HAM-D T0−T1: t = 4.056 p = 0.001; T1−T2: t = 1.908 p = 0.070; MADRS T0−T1: t = 3.784 p = 0.001; T1−T2: t = 1.915 p = 0.069; MEL T0−T1: t = 3.887 p = 0.001; T1−T2: t = 1.825 p = 0.082). There were no side effects during or after treatment with tDCS. Conclusions: Preliminary data suggest a good efficacy and tolerability of tDCS in the acute treatment of depressive symptoms, particularly of the melancholic items of drug-resistant depressed patients