Improving working memory in schizophrenia: Effects of 1 mA and 2 mA transcranial direct current stimulation to the left DLPFC

Modulation of brain activity with transcranial direct current stimulation: Targeting regions implicated in impaired illness awareness in schizophrenia

“…Previous investigations have reported on the cognitive benefits of single-session tDCS, particularly in improving working memory and learning in patients with schizophrenia [46][47][48]. Although we did not observe a main effect of tDCS in improving cognitive insight, post-hoc exploratory analyses showed that bifrontal stimulation reduced 'self-certainty' subscale scores (Supplemental Material 8).…”

Targeting cognition in schizophrenia through transcranial direct current stimulation: A systematic review and perspective

“…Four studies (Hoy et al, 2014, Hoy et al, 2015, Impey et al, 2017 found behavioural effects (accuracy) of 2 mA tDCS that were not observed for 1 mA stimulation. The opposite effect was reported by Papazova et al (2018) and Orlov et al (2017a) who found improvement on the WM n-back task (accuracy but no reaction times) only 24-hours post-stimulation with 2 mA but not immediately after treatment (see also findings by (Hoy et al, 2016, Rassovsky et al, 2018). Moreover, Rassovsky et al (2018) compared cathodal with anodal stimulation over the dlPFC in a working memory task and surprisingly found improvement in accuracy in the sham condition compared to both other treatments.…”

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

“…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).…”

“…Brief Assessment of Cognition in Schizophrenia, Mellin andTrail Making Test, Palm and. 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.…”