Abstract
Background
Treatments for cognitive dysfunction in neuropsychiatric conditions are urgently needed.
Cognitive training and transcranial direct current stimulation (tDCS) hold promise,
and there is growing interest in combined or multimodal treatments, though studies
to date have had small samples and inconsistent results.
Methods
A systematic review and meta-analysis was completed. Retained studies included cognitive
training combined with active or sham tDCS in a neuropsychiatric population and reported
a posttreatment cognitive outcome. Meta-analyses included effect sizes comparing cognitive
training plus active tDCS and cognitive training plus sham tDCS in 5 cognitive domains.
Risk of bias in included studies and across studies was explored.
Results
Fifteen studies were included: 10 in neurodegenerative disorders and 5 in psychiatric
disorders (n = 629). There were several tDCS montages, though two-thirds of studies placed the
anode over the left dorsolateral prefrontal cortex. A wide variety of cognitive training
types and outcome measures were reported. There was a small, statistically significant
effect of combined treatment on measures of attention/working memory, as well as small
and non–statistically significant effects favoring combined treatment on global cognition
and language. There was no evidence of bias in individual studies but some evidence
of nonreporting or small-study bias across studies.
Conclusions
These results may provide preliminary support for the efficacy of combined cognitive
training and tDCS on measures of attention/working memory. More data are needed, particularly
via studies that explicitly align the cognitive ability of interest, stimulation target,
training type, and outcome measures.
Keywords
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Article info
Publication history
Published online: October 12, 2022
Accepted:
September 19,
2022
Received in revised form:
August 25,
2022
Received:
June 16,
2022
Identification
Copyright
© 2022 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
