Efficacy of non-invasive brain stimulation in reducing craving in patients with alcohol use disorder: systematic review and meta-analysis

BACKGROUND

Craving plays a central role in reinforcing alcohol use disorder (AUD), and non-invasive brain stimulation (NIBS) has shown potential as a therapeutic intervention in AUD. We aim to evaluate the efficacy and safety following the application of NIBS in patients with AUD.

METHODS

A search of the PubMed, EMBASE, Cochrane Library and PsycINFO databases for articles published up to June 30, 2024 using predefined search terms identified a total of 20 randomized controlled trials (RCTs) and 22 units. The primary outcome of this study was the change in craving severity. The secondary outcome was the rate of adverse events.

RESULTS

Comparing the effect of alcohol craving severity reduction between the NIBS group and the sham group, the NIBS group showed a significant reduction in alcohol craving severity compared to the sham group (SMD = -0.211; 95% CI = -0.379 to -0.042). The I2 value was 22.2%, indicating a low level of heterogeneity (p = 0.17). Regarding safety, the NIBS group had an increased rate of adverse events compared to the sham group, but this was not significant (OR = 1.494; 95% CI = 0.834 to 2.675). In a subgroup analysis based on the types of NIBS, only transcranial direct current stimulation showed a significant effect (SMD = -0.214; 95% CI = -0.427 to -0.002). Subgroup analyses of stimulation parameters in NIBS showed that a significant reduction in craving severity was observed when NIBS was applied to the dorsolateral prefrontal cortex (SMD = -0.200; 95% CI = -0.381 to -0.019) and when multiple sessions were administered (SMD = -0.388; 95% CI = -0.620 to -0.156). In addition, a significant reduction in craving severity due to delayed effects was observed even 4 weeks after the last stimulation (SMD = -0.553; 95% CI = -0.979 to -0.126), but this finding should be interpreted with caution.

CONCLUSIONS

NIBS is effective in reducing the severity of craving in patients with AUD. This study provides the latest evidence on the effect of NIBS in reducing craving severity in AUD patients.

Application of Transcranial Direct Current Stimulation in Sleep Disturbances

Sleep disturbances are common across all age groups, and they encompass a broad range of impairments of daytime functioning and comorbid various clinical conditions. However, current treatment methods for sleep disturbances have several limitations. As the ‘top-down’ pathway is known to play an important role in sleep-wake regulation, and as neuronal activity abnormalities have been reported as a potential pathological mechanism of sleep disturbances, the use of non-invasive brain stimulation—such as transcranial direct current stimulation (tDCS) in treating sleep disturbances—has emerged. In the present review, we first explain the mechanism of tDCS, and we also introduce recent studies that have applied tDCS to sleep disorders, along with other sleep-related tDCS studies. In conclusion, many studies have achieved improvements in sleep state, although some of these studies have reported inconsistent effects of tDCS according to the protocol and the conditions used. Further studies are needed to explore the optimal protocols to use when applying tDCS in each sleep disturbance and to enhance the evidence on the clinical efficacy of tDCS.

Effects of Acceptance and Commitment Therapy and Repetitive Transcranial Magnetic Stimulation on Obsessive-Compulsive Disorder

Objective: This study aims to explore the difference of clinical efficacy and psychological flexibility of sertraline hydrochloride combined with acceptance and commitment therapy (ACT) or repeated transcranial magnetic stimulation (rTMS) in patients with obsessive-compulsive disorder (OCD). Materials and Methods: Sixty-three inpatients diagnosed with OCD were randomly divided into ACT group (N = 32) and rTMS group (N = 31), both of which were combined with sertraline hydrochloride. The following assessments were completed by the Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Symptom Checklist 90 (SCL-90), Acceptance and Action Questionnaire (AAQ-II), and Cognitive Fusion Questionnaire (CFQ) during pretreatment, 4 weeks posttreatment, and 8-week follow-up. Results: After treatment: (1) the SCL-90 score of two groups significantly decreased from pretreatment to 8-week follow-up (P < 0.01 and P < 0.001); (2) The HAMA, HAMD, and Y-BOCS scores of the two groups significantly decreased from pretreatment to 8-week follow-up (P < 0.001 and P < 0.05); (3) No statistically significant difference of the SCL-90, HAMA, HAMD and Y-BOCS between two groups; (4) The AAQ-II and CFQ scores of the ACT group significantly decreased from 4 weeks posttreatment to 8-week follow-up (P < 0.01). However, no statistically significant difference was observed in the rTMS group (P > 0.05). Conclusions: Overall, our study suggested that sertraline hydrochloride combined with ACT or rTMS can improve the obsessive-compulsive symptoms, anxiety, and depression and has equivalent efficacy. Moreover, ACT can more effectively and durably improve the psychological flexibility of patients compared with rTMS.

Meta-Analysis on the Effects of Transcranial Direct Current Stimulation on Naming of Elderly with Primary Progressive Aphasia

Purpose: This study aimed to conduct a qualitative evaluation by synthesizing previous studies on the effect of transcranial direct current stimulation (tDCS) on primary progressive aphasia (PPA)'s naming ability and prove the effects of tDCS mediation on PPA naming using meta-analysis. Methods: This study searched literature published from January 2000 to July 2019 using four academic databases (i.e., PubMed, Web of Science, MEDLINE, and Cochrane Library). The final seven publications were systematically evaluated and meta-analysis was conducted for two papers. The effect size was estimated by a standard mean difference (SMD) using Hedge's g, and the significance of effect size was confirmed using the 95% confidence interval. Results: The results of seven previous studies' quality assessments ranged from 15 to 26, which were rated above adequate. The results of the meta-analysis showed that the effect size was 0.82 (95% CI: 0.16-1.47), which was a significant 'large effect'. Conclusions: This meta-analysis proved that tDCS intervention significantly improved the naming performance of PPA. Future studies must confirm the effects of tDCS on naming intervention by using meta-analysis including many RCT studies.