Determining the Effects of Transcranial Direct Current Stimulation on Tinnitus, Depression, and Anxiety: A Systematic Review

Abstract

(1) Background: Tinnitus is the awareness of a sound in the absence of an external source. It affects around 10–15% of people, a significant proportion of whom also experience symptoms such as depression or anxiety that negatively affect their quality of life. Transcranial direct current stimulation (tDCS) is a technique involving constant low-intensity direct current delivered via scalp electrodes. It is a potential treatment option for tinnitus, as well as tinnitus-related conditions such as depression and anxiety. This systematic review estimates the effects of tDCS on outcomes relevant to tinnitus. In addition, it sheds light on the relationship between stimulation parameters and the effect of tDCS on these outcomes; (2) Methods: Exhaustive searches of electronic databases were conducted. Randomised controlled trials were included if they reported at least one of the following outcomes: tinnitus symptom severity, anxiety, or depression. Where available, data on quality of life, adverse effects, and neurophysiological changes were also reviewed. GRADE was used to assess the certainty in the estimate; (3) Results: Meta-analyses revealed a statistically significant reduction in tinnitus (moderate certainty) and depression (low certainty)-but not anxiety-following active tDCS compared to sham control. Network meta-analyses revealed potential optimal stimulation parameters; (4) Conclusions: The evidence synthesised in this review suggests tDCS has the potential to reduce symptom severity in tinnitus and depression. It further narrows down the number of potentially optimal stimulation parameters.

Efficacy of Transcranial Direct Current Stimulation (tDCS) on Cognition, Anxiety, and Mobility in Community-Dwelling Older Individuals: A Controlled Clinical Trial

“…Anxiety was included in this study because the same area used for cognitive stimulation has been shown to be effective in improving neuropsychiatric symptoms [26]. However, unlike other studies [35,36], our findings did not show significant improvements in anxiety. We attribute this outcome to the deliberate selection of older individuals without a previous history of psychiatric disorders and who only exhibited "possible symptoms of anxiety", as indicated by their HADS scores.…”

Effect of transcranial direct current stimulation on postpartum depression: A study protocol for a randomized controlled trial

“…However, the highly unstable electrode montage in the tDCS study may make the results inaccurate. The outcomes of a previous meta-analysis on the duration and length of tDCS sessions offer us an opportunity to further optimize this intervention (Labree et al, 2022 ). Relevant studies (Narita et al, 2017 ) also demonstrate the efficacy of the designed controlled trial for evaluating the effect of tDCS on the treatment of PPD.…”

State of the art: non-invasive electrical stimulation for the treatment of chronic tinnitus

“…Several excellent related narrative or systematic reviews have recently been published. [28][29][30][31][32][33] However, these reviews inevitably lose some information of this theme due to exclusion of unqualified studies or the limited scope. Therefore, this review sought to bring together the continuous work from the literature and summarize the existing types of non-invasive electrical stimulation (NIES) and their application value in tinnitus treatment without excluding studies based on their quality.…”