Clinical Psychology and Personality

Clinical Psychology and Personality

Investigating the Effectiveness of Transcranial Direct Current Stimulation (tDCS) of the Brain on Impulsivity and Working Memory in Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD)

Document Type : Original Article

Authors
1 PhD Student in psychology, Science and Arts University, Yazd, Iran
2 PhD in Cognitive Neurosciences, Associate Professor, Science and Arts University, Yazd, Iran
Abstract
Introduction: Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that modulates cortical excitability by applying a low-intensity electrical current to the scalp. This study aimed to evaluate the effectiveness of tDCS on impulsivity and working memory in adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD).
Method: This study employed a quasi-experimental design with pretest-posttest measures and a control group. The statistical population comprised adolescent clients from counseling centers in Yazd in 2024. The sample included 30 adolescents aged 12 to 18 years diagnosed with ADHD, selected through convenience sampling. Participants were randomly assigned to either the intervention group (n = 15) or the control group (n = 15). The research instruments consisted of the N-back working memory test and the Barratt Impulsiveness Scale (BIS-11). Data were analyzed using analysis of covariance (ANCOVA) with SPSS version 25.
Results: The findings demonstrated that transcranial direct current stimulation significantly affected impulsivity and working memory in adolescents with ADHD. After controlling for pretest scores, a significant difference was observed between the two groups, indicating a reduction in impulsivity and an improvement in working memory (Impulsivity: F(1,27) = 53.21, p = 0.001; Working Memory: F(1,27) = 50.23, p = 0.001). The effect sizes were η² = 0.47 for impulsivity and η² = 0.39 for working memory, highlighting the strong impact of the intervention.
Discussion and conclusion: Transcranial direct current stimulation (tDCS) of the brain had a significant effect on impulsivity and working memory in adolescents with attention deficit hyperactivity disorder (ADHD). After controlling for pre-test effects on post-test scores, there was a significant difference between the two groups at the 0.05 significance level, indicating a decrease in impulsivity and an improvement in working memory. The findings indicate that transcranial direct current stimulation effectively reduces impulsivity and enhances working memory in adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD).
Keywords

1-    Ayatnia1 F, Mirzaie P. T he Effect of Transcranial Direct-Current Stimulation of Brain (tdcs) on Cognitive Ability and Working Memory of Students with Attention Deficit Hyperactivity Disorde. N‌europsychology. 2022  Winter; 4(27): 37-46. https://www.ensani.ir/file/download/article/1671510222-10112-27-3.pdf   [In Persian]
2-    Taghizadeh Hir, S., Narimani, M., Aghajani, S., Nadrmohammadi, M., & Basharpoor, S. (2023). Comparison of the Effectiveness of Transcranial Direct Current Brain Stimulation (tDCS) and Computer-based Cognitive Rehabilitation on Improving Cognitive Emotion Regulation in Children with Attention deficit/hyperactivity Disorder. Biquarterly Journal of Cognitive Strategies in Learning. 2023; 12(22): 87–106.
[In Persian]
3-    Mikaeli N, Mousavi S. Effectiveness of transcranial direct current stimulation (TDCS) on improvement of attention deficit hyperactivity disorder (ADHD) in children and adolescents. The Second National Conference on Psychotherapy in Iran(incpuma2.ir). https://isnac.ir/XEFZ-HGECG
4-    Erfani Nasab, M., Faramarzi, S., Sharifi, A. (2025). The Effectiveness of Transcranial Direct Current Stimulation along with Computerized Cognitive Training on the Executive Functions and Academic Performance among Students with Specific Learning Disorder comorbid with Attention Deficit Hyperactivity Disorder. Journal of Cognitive Strategies in Learning. 2052; 12(23): 19–41.
5-    Soleymani, M., & Kazemimonir, N. (2020). The Effectiveness of Transcranial Direct Current Stimulation (T DCS) on increase Cognitive Flexibility and Processing Speed among children with Attention Deficit/Hyperactivity (ADHD). Educational Psychology, 16(57), 305–326. https://doi.org/10.22054/jep.2020.56456.3181. [In Persian]
6-    Kord, M., Fath-Abadi, J., Gharibzadeh, S., & Khosrowabadi, R. (2025). Enhancing EEG components in adolescents with ADHD using transcranial electrical stimulation: A randomized-active controlled study. Basic and Clinical Neuroscience, 16(Special Issue), 353–356.
7-    Nejati, V., Hadian Rasanan, A. H., Amani Rad, J., Movahed Alavi, M., Haghi, S., & Nitsche, M. A. (2022). Transcranial direct current stimulation (tDCS) alters the pattern of information processing in children with ADHD: Evidence from drift diffusion modeling. Neurophysiologie Clinique, 52(1), 17–27.
8-    Amouzadeh, F., Gharayagh Zandi, H., Moradi Sabzevar, M., Rostami, R., & Moghadam Zadeh, A. (2021). Impact of video game Minecraft on the cognitive flexibility of ADHD athletes student. Shenakht Journal of Psychology and Psychiatry, 8(2), 24–38.
9-    Amouzadeh, F., Moradi, H., Zandi, H., Rostami, R., & Moghadamzadeh, A. (2022). Impact of transcranial direct current stimulation (tDCS) on the visual sustain attention of ADHD student-athletes. Journal of Sports and Motor Development and Learning, 14(2), 17–33.
10- Salehinejad MA, Wischnewski M, Nejati V, Vicario CM, Nitsche MA. Transcranial direct current stimulation in attention-deficit hyperactivity disorder: A meta-analysis of neuropsychological deficits. PLoS One. 2019; 14(4): e0215095.
11- Barkley RA. Attention-Deficit Hyperactivity Disorder: A handbook for diagnosis and treatment (4th ed.). Guilford Press. 2022
12- Estaji R, Hosseinzadeh M, Arabgol F, Nejati V. Transcranial direct current stimulation (tDCS) improves emotion regulation in children with attention-deficit hyperactivity disorder (ADHD). Sci Rep. 2024; 14: 13889.
13- Jacobson LA, Crocetti D, Dirlikov B, Slifer K, Denckla MB, Mostofsky SH, Mahone EM. Anomalous Brain Development Is Evident in Preschoolers With Attention-Deficit/Hyperactivity Disorder. Journal of the International Neuropsychological Society. 2018; 24(6): 531–539.
14- Bannett Y, Luo I, Azuero-Dajud R, Feldman HM, Brink FW, Froehlich TE, Harris HK, Kan K, Wallis KE, Whelan K, Spector L, Forrest CB. ADHD Diagnosis and Timing of Medication Initiation Among Children Aged 3 to 5 Years. JAMA Netw Open. 2025; 8(8): e2529610.
15- Wang Y, Liu J, Wu Y, Wei Y, Xie H, Zhang T, Zhang Z. A randomized, sham-controlled trial of high-definition transcranial direct current stimulation on the right orbital frontal cortex in children and adolescents with attention-deficit hyperactivity disorder. Front Psychiatry. 2023; 14: 987093. https://doi.org/10.3389/fpsyt.2023.987093
16- Centers for Disease Control and Prevention. Data and statistics on ADHD [Internet]. Atlanta: CDC; 2024 [cited 2026 Aug 27]. Available from: https://www.cdc.gov/adhd/data/index.html
17- Krauel K, Brauer H, Breitling-Ziegler C, Freitag CM, Luckhardt C, Mühlherr A, Schütz M, Boxhoorn S, Ecker C, Castelo-Branco M, Sousa D, Pereira HC, Crisóstomo J, Schlechter F, Wrachtrup Calzado I, Siemann J, Moliadze V, Splittgerber M, Damiani G, Salvador RN, Ruffini G, Nowak R, Braboszcz C, Soria-Frisch A, Thielscher A, Buyx AM, Siniatchkin M, Dempfle A, Prehn-Kristensen A. Prefrontal transcranial direct current stimulation in pediatric attention-deficit/hyperactivity disorder: A randomized clinical trial. JAMA Netw Open. 2025; 8(2): e2460477. https://doi.org/10.1001/jamanetworkopen.2024.60477
18- You G, Pan X, Li J, Zhao S. Effects of transcranial direct current stimulation on modulating executive functions in healthy populations: A systematic review and meta-analysis. Front Hum Neurosci. 2024; 18: 1485037. https://doi.org/10.3389/fnhum.2024.1485037
19- Kessi M, Duan H, Xiong J, Chen B, He F, Yang L, et al. Attention-deficit/hyperactive disorder update. Front Mol Neurosci. 2022; 15: 925049. doi:10.3389/fnmol.2022.925049.
20- Li J, Hou X, Fan Q,  Chen L. Efficacy and safety of transcranial direct current stimulation in ADHD: systematic review and meta-analysis. Frontiers in Psychiatry ADHD. 2026; 17(1): 123-147. doi: 10.3389/fpsyt.2026.1747588
21- Danielson Danielson ML, Claussen AH, Bitsko RH, Katz SM, Newsome K, Blumberg SJ, Kogan MD, Ghandour R. ADHD Prevalence Among U.S. Children and Adolescents in 2022: Diagnosis, Severity, Co-Occurring Disorders, and Treatment. J Clin Child Adolesc Psychol. 2024; 53(3): 343-360.
22- Tahmasebi S, Karim Pourozife Khurani A. Comparing the effectiveness of two motivational manipulation methods and neurofeedback on reward sensitivity, delay discounting, and impulsivity in children with attention deficit/hyperactivity disorder. Iran Journal Psychiatry Clin Psychol. 2021; 27(4): 458-473 [In Persian]
23- Azizi Aram S, Basharpour S, Atadokht A, Molavi P. The effectiveness of transcranial direct current stimulation (TDCS) on improving emotion regulation and dysfunctional attitudes in individuals with borderline personality disorder. Journal Rouysh-e Ravanshenasi. 2021; 10(7): 115-126. [In Persian]
24- Kirchner WK. Age differences in short-term retention of rapidly changing information. J Exp Psychol. 1958; 55(4): 352-358.
25- Cosmo C, DiBiasi M, Lima V, Grecco LC, Muszkat M, Philip NS, de Sena EP. A systematic review of transcranial direct current stimulation effects in attention-deficit/hyperactivity disorder. J Affect Disord. 2020; 276: 1-13. https://doi.org/10.1016/j.jad.2020.06.054
26- Zhang M, Ma C, Liu Y, Ma X, Liu T, Jia F, Du L. Efficacy and safety of transcranial direct current stimulation for children and adolescents with attention-deficit/hyperactivity disorder: a systematic review and meta-analysis. Journal of Psychiatry and Neuroscience. 2025; 50(4): E248-E266. https://doi.org/10.1503/jpn.250032
27- Chen Q, Pan N, Long Y, Qin K, Sangchooli A, Cao Y, Singh MK, Chen Y, Gong Q. Noninvasive Brain Stimulation in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Treatment Efficacy and Targeting Strategies. Journal of the American Academy of Child & Adolescent Psychiatry. 2026; 65(3): 369-391.
28- Yin Y, Wang X, Feng T. Noninvasive Brain Stimulation for Improving Cognitive Deficits and Clinical Symptoms in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis. Brain Sci. 2024; 14(12): 1237.
29- Kofler MJ, Singh LJ, Soto EF, Chan ESM, Miller CE, Harmon SL, Spiegel JA. Working memory and short-term memory deficits in ADHD: A bifactor modeling approach. Neuropsychology. 2020; 34(6): 686–698.
30- Irwin LN, Soto EF, Chan ESM, Miller CE, Carrington-Forde S, Groves NB, Kofler MJ. Activities of daily living and working memory in pediatric attention-deficit/hyperactivity disorder (ADHD). Child Neuropsychol. 2021; 27(4): 468–490. https://doi.org/10.1080/09297049.2020.1866521
31- Mohammadzadeghan R, Farid A, Chalabianlu Hasratanlo G, Mesrabadi J. Comparison of the effectiveness of mindfulness-based social-emotional learning program with/and without transcranial direct current stimulation on emotional self-regulation and problem-solving performance in students with attention-deficit/hyperactivity disorder. Shefaye Khatam. 2023; 11(2): 52-64. [In Persian]
32- Chrysikou EG, Wing EK, van Dam WO. Transcranial direct current stimulation over the prefrontal cortex in depression modulates cortical excitability in emotion regulation regions as measured by concurrent functional magnetic resonance imaging: an exploratory study. Biol Psychiatry Cogn Neurosci Neuroimaging. 2022; 7(1): 85–94.
33- Salvi C, Beeman M, Bikson M, McKinley R, Grafman J. TDCS to the right anterior temporal lobe facilitates insight problem-solving. Sci Rep. 2020; 10: 946. doi:10.1038/s41598-020-57724-1
34- Zhang M, Ma C, Liu Y, Ma X, Liu T, Jia F, Du L. Efficacy and safety of transcranial direct current stimulation for children and adolescents with attention-deficit/hyperactivity disorder: a systematic review and meta-analysis. J Psychiatry Neurosci. 2025; 50(4): E248–E266. https://doi.org/10.1503/jpn.250032
35- Westwood SJ, Criaud M, Lam SL, Lukito S, Wallace-Hanlon S, Kowalczyk OS, Kostara A, Mathew J, Agbedjro D, Wexler BE, Cohen Kadosh R, Asherson P, Rubia K. Transcranial direct current stimulation (tDCS) combined with cognitive training in adolescent boys with ADHD: a double-blind, randomised, sham-controlled trial. Psychol Med. 2023; 53(2): 497–512. https://doi.org/10.1017/S0033291721001859
36- Salehinejad MA, Wischnewski M, Nejati V, Vicario CM, Nitsche MA. Transcranial direct current stimulation in attention-deficit hyperactivity disorder: a meta-analysis of neuropsychological deficits. PLoS One. 2019; 14(4): e0215095.
37- Delavar A. Ravesh-e tahghigh dar ravanshenasi va olum-e tarbivati [Research methods in psychology and education]. Tehran: Virayesh; 2015. [In Persian]
38- Bush G, Spencer TJ, Holmes J, Shin LM, Valera EM, Seidman LJ, Makris N, Surman C, Aleardi M, Mick E, Biederman J. Functional magnetic resonance imaging of methylphenidate and placebo in attention-deficit/hyperactivity disorder during the multi-source interference task. Arch Gen Psychiatry. 2008; 65(1): 102–114.
39- Kasaean K, Kiamanesh A, Bahrami H. Comparison of working memory performance and attention maintenance in students with and without learning disabilities. Journal Learn Disabil. 2014; 4(3): 112-123. [In Persian]
40- Almasi M, Noroozi Homayoon M, Sharif A. The effectiveness of neurofeedback therapy and transcranial direct stimulation in cognitive dominance of children with attention deficit/hyperactivity disorder. Neuropsychology. 2021; 7(2): 111–130.
41- Taghizadeh R, Nejati V, Mohammadzadeh A, Akbarzadeh Baghban A. Study of the development of auditory and visual working memory in elementary school students. Journal Res Rehabil Sci. 2014; 10(2): 239-249.
[In Persian]
42- Patton JH, Stanford MS, Barratt ES. Factor structure of the Barratt Impulsiveness Scale. J Clin Psychol. 1995; 51(6): 768–774.
43- Javid M, Mohammadi N, Rahimi CH. Psychometric properties of the Persian version of the 11th edition of the Barth Monogamy Scale. Psychol Methods Models. 2012; 2(8): 23-34.
[In Persian]
44- Gandiga PC, Hummel FC, Cohen LG. Transcranial DC stimulation (tDCS): a tool for double-blind sham-controlled clinical studies in brain stimulation. Clin Neurophysiol. 2006; 117(4): 845–850.
45- Fregni F, Liguori P, Fecteau S, Nitsche MA, Pascual-Leone A, Boggio PS. Cortical stimulation of the prefrontal cortex with transcranial direct current stimulation reduces cue-provoked smoking craving: a randomized, sham-controlled study. J Clin Psychiatry. 2008; 69(1): 32–40.
46- Ramezani Gol-Afzani N, Karami A, Rostami R. The effect of electrical brain stimulation using direct current on verbal working memory of children with intellectual disabilities. Sci Res J Psychol Methods Models. 2021; 12(45): 49–58. https://doi.org/10.30495/jpmm.2021.26570.3245. [In Persian]
47- Rubia K, Westwood S, Aggensteiner PM, Brandeis D. Neurotherapeutics for attention deficit/hyperactivity disorder (ADHD): a review. Cells. 2021; 10(8): 2156.