Delayed effect of bifrontal transcranial direct current stimulation in patients with treatment-resistant depression: a pilot study

Abstract

Background Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique, which has yielded promising results in treating major depressive disorder. However, its effect on treatment-resistant depression remains to be determined. Meanwhile, as an emerging treatment option, patients’ acceptability of tDCS is worthy of attention. Methods This pilot study enrolled 18 patients (wome n = 13) with treatment-resistant unipolar ( n = 13) or bipolar ( n = 5) depression. Twelve sessions of tDCS were administered with anode over F3 and cathode over F4. Each session delivered a current of 2 mA for 30 min per ten working days, and at the 4th and 6th week. Severity of depression was determined by Montgomery–Åsberg Depression Rating Scale (MADRS); cognitive performance was assessed by a computerized battery. Results Scores of MADRS at baseline (29.6, SD = 9.7) decreased significantly to 22.9 (11.7) ( p = 0.03) at 6 weeks and 21.5 (10.3) ( p = 0.01) at 8 weeks. Six (33.3%) participants were therapeutically responsive to tDCS. MADRS scores of responders were significantly lower than those of non-responders at the 6th and 8th week. Regarding change of cognitive performance, improved accuracy of paired association ( p = 0.017) and social cognition ( p = 0.047) was observed at the 8th week. Overall, tDCS was perceived as safe and tolerable. For the majority of patients, it is preferred than pharmacotherapy and psychotherapy. Conclusions TDCS can be a desirable option for treatment-resistant depression, however, its efficacy may be delayed; identifying predictors of therapeutic response may achieve a more targeted application. Larger controlled studies with optimized montages and sufficient periods of observation are warranted. Trial registration This trial has been registered at the Chinese Clinical Trial Registry ( ChiCTR-INR-16008179 ).

Effects of Transcranial Direct Current Stimulation on Information Processing Speed, Working Memory, Attention, and Social Cognition in Multiple Sclerosis

“…The idea of modulating social cognition by tDCS targeting the prefrontal cortex stems from studies showing the involvement of this region in social cognition (73), and its relationship with social cognitive deficits in MS (10). Unlike our study, 12 sessions of bifrontal tDCS improved social cognition in depressed patients (74). Moreover, a single session of anodal tDCS ameliorated social cognitive measures in healthy individuals [left prefrontal anodal stimulation, right frontopolar cathode; (75)], as in patients with neurodegenerative diseases [medial prefrontal anodal stimulation; in frontotemporal dementia (76) and in Parkinson's disease (77)].…”

Reliability, sensitivity, and predictive value of fMRI during multiple object tracking as a marker of cognitive training gain in combination with tDCS in stroke survivors

“…As our main aim was to identify potential fMRI‐based markers for training outcome, we did not assess possible cognitive and clinical transfer effects, which will be relevant for evaluating clinical relevance, and further studies are needed to establish the premises for optimizing the clinical potential for working memory interventions in individual stroke patients. It has furthermore been reported that potential beneficial effects of tDCS may emerge at a delayed stage after intervention (Goodwill, Teo, Morgan, Daly, & Kidgell, 2016; Li et al, 2019). As our last assessment was performed shortly after the final stimulation, any delayed effects may have been lost.…”

In-vivo imaging of targeting and modulation of depression-relevant circuitry by transcranial direct current stimulation: a randomized clinical trial

“…refs. 11 , 13 , 23 – 27 ), using stereotaxic mapping of brain coordinates in each individual. We hypothesized that Active-tDCS targeted at the left DLPFC would induce significant magnetic fields during stimulation in the same region, according to Ampere’s Law (hypothesis#1).…”