Effects of Transcranial Direct-Current Stimulation (tDCS) Treatment Sessions on Neuropsychological ‎Functioning Among Detoxified Inpatients with Alcohol Dependence: A Randomized Sham-Controlled Clinical Trial

ABSTRACT

Individuals with alcohol dependence often experience cognitive dysfunction after detoxification, which can persist even after sustained abstinence. Transcranial direct current stimulation (tDCS) has shown promise in improving cognitive functioning in these patients. The main objective of this research was to assess the impact of ten sessions of transcranial direct-current stimulation (tDCS) targeting the dorsolateral prefrontal cortex (DLPFC) on the neuropsychological functioning of hospitalized individuals with alcohol dependence who have undergone detoxification. This single-center, parallel, and single-blind randomized controlled trial assessed the effects of ten sessions of add-on tDCS treatment on neuropsychological functions. 44 recently detoxified alcohol-dependent inpatients were randomly assigned to either treatment as usual (TAU) plus ten sessions of active tDCS over left DLPFC, or TAU plus ten sessions of sham tDCS and assessed the effect of tDCS sessions and time on neuropsychological functions. Neuropsychological functions were evaluated in inpatients undergoing treatment for alcohol dependence at T1 (9.95 + 2.42 days abstinence) and T2 (19 ± 1.48 days abstinence), and while time had a significant impact on mean scores of various neuropsychological tests, neither active tDCS treatment nor its interaction with time displayed a significant effect on neuropsychological functioning, as revealed by two-way ANOVAs with repeated measurements. In detoxified inpatients with alcohol dependence, tDCS treatment was not found to have a significant impact on neuropsychological functioning when compared to sham treatment, whereas abstinence from alcohol for approximately three weeks resulted in significant improvements in various cognitive domains including mental speed, verbal learning & memory, visual memory, verbal fluency, and response inhibition.

KEYWORDS:

• Transcranial direct-current stimulation (tDCS)
• dorsolateral prefrontal cortex (DLPFC)
• verbal learning & memory
• response inhibition
• verbal fluency
• alcohol dependence

Acknowledgments

Without the efforts and willingness of our patients & their families to participate in the study protocol, this work would not have been a possibility. Thereby, we wish to extend our gratitude to the patients & their family members along with the medical staff at NDDTC, AIIMS indulged in delivering patient-care-related services and proved to be a helping hand.

Disclosure statement

No potential conflict of interest was reported by the author(s).

CRediT authorship contribution statement

All authors commented on and contributed to the final draft. All authors approved the final version for submission.

Additional information

Funding

This study was supported by grants from the Cognitive Science Research Initiative (CSRI, Department of Sciences and Technology (DST/CSRI/2017/149), Ministry of Science and Technology, Government of India, and by the use of relevant resources and facilities available at the National Drug Dependence Treatment Centre, All India Institute of Medical Sciences, New Delhi, India.