Beneficial effects of anodal transcranial direct current stimulation (tDCS) on spatial working memory in patients with schizophrenia

Enhancing cognitive control training with transcranial direct current stimulation: a systematic parameter study

“…Particularly relevant for the clinical context, these findings imply that a simple increase of stimulation intensity does not necessarily enhance efficacy but, by contrast, might compromise efficacy of the respective intervention. Nevertheless, clinical populations may require higher stimulation intensities due to pathology-or medication-dependent impairments of neuroplasticity [74,75]. Finally, laterality of tDCS modulating potentially lateralised cognitive functions might be critical for yielding effects, as shown by our present and previous studies [16].…”

Transcranial Direct Current Stimulation and Cognition in Neuropsychiatric Disorders: Systematic Review of the Evidence and Future Directions

“…Brief Assessment of Cognition in Schizophrenia, Mellin and others 2018 and Trail Making Test, Palm and others 2016). Indeed, trials that applied computerized and more specific testing for the selected cognitive measure demonstrated WM performance amelioration using the n-back task (Hoy and others 2014; Nienow and others 2016; Orlov and others 2017b; Schwippel and others 2018). This is particularly true for trials that combined tDCS with cognitive training (Nienow and others 2016; Orlov and others 2017b), evidencing long-term effects of tDCS on WM performance, which were maintained for longer than 1 month (Orlov and others 2017b), thus confirming a more effective impact of stimulation when administered in conjunction with a task that activates the targeted network.…”

“…Full-text versions of the remaining 55 records were then screened for eligibility, and this process excluded a further 14 studies. In the time period until January 2020, 41 studies (Bennabi and others 2015; Bersani and others 2017; Boggio and others 2009, 2012, Brunoni and others 2014; Brunoni and others 2016; Bystad and others 2016; Cotelli and others 2014; Ferrucci and others 2008; Fregni and others 2006; Gögler and others 2017; Hoy and others 2014; Khedr and others 2014; Knechtel and others 2014; Loo and others 2010; Loo and others 2012; Loo and others 2018; Martin and others 2015; Meinzer and others 2015; Mellin and others 2018; Moreno and others 2015; Nienow and others 2016; Oliveira and others 2013; Orlov and others 2017a; Orlov and others 2017b; Palm and others 2012, 2016; Papazova and others 2018; Pavlova and others 2018; Powell and others 2014; Rassovsky and others 2015, 2018; Reinhart and others 2015a; Roncero and others 2017; Schwippel and others 2018; Segrave and others 2014; Smith and others 2015; Suemoto and others 2014; Vercammen and others 2011; Wolkenstein and Plewnia, 2013; Yun and others 2016), published between 2006 and 2018, met all inclusion criteria and were included in the current systematic review. See Supplemental Material for PRISMA flow diagram, and further description of included and excluded studies.…”

“…Given that the effect of tDCS may persist several days after stimulation (Gálvez and others 2013; Khedr and others 2014; Park and others 2019), we considered as an appropriate wash-out period a 2-week interval, and deemed as unbiased only crossover trials where wash-out was properly performed. Thirty-seven percent of studies raised some concerns pertaining to the randomization process (i.e., no information about concealment of the allocation sequence) (Boggio and others 2012; Brunoni and others 2014; Fregni and others 2006; Loo and others 2010; Reinhart and others 2015a; Roncero and others 2017; Schwippel and others 2018), unclear effect of assignment to intervention (i.e. lack of appropriate analysis accounting for potential effects of drop-outs) (Bennabi and others 2015; Bystad and others 2016; Loo and others 2018; Mellin and others 2018; Orlov and others 2017a; Palm and others 2016; Smith and others 2015), or both (Cotelli and others 2014).…”

Anodal tDCS applied to the left frontal cortex abrogates scopolamine-induced fear memory deficit via the dopaminergic system

“…Previous experiments have demonstrated that anodal tDCS increases cerebral blood flow (Merzagora et al, 2010), and enhances neural plasticity in the brain (Fritsch et al, 2010;Jiang et al, 2012). Many clinical studies have reported that anodal tDCS provides therapeutic benefits in patients with various neurological disorders, such as stroke (Hummel et al, 2005), multiple system atrophy (Alexoudi et al, 2018), schizophrenia (Schwippel et al, 2018), Parkinson's (Fregni et al, 2006) and Alzheimer's (Ferrucci et al, 2008) disease. The therapeutic potential of anodal tDCS for cognitive decline in the rat model of streptozotocin-induced diabetic (Wu et al, 2017), traumatic brain injury (Yoon et al, 2016), attention deficit/hyperactivity (Leffa et al, 2015), and Alzheimer's disorder (Yu et al, 2015) has been supported.…”