# Combined tDCS and Neuropsychological Treatment for Adult ADHD: A Single-Case Feasibility Study on Cognitive and Emotional Outcomes

## TL;DR

A treatment combining brain stimulation and therapy improved cognitive and emotional outcomes in an adult with ADHD.

## Contribution

This study demonstrates the feasibility and safety of a non-pharmacological, multimodal treatment for adult ADHD.

## Key findings

- The combined treatment improved cognitive flexibility, visual working memory, and planning.
- Depressive symptoms and quality of life in physical and psychological domains significantly improved.
- The treatment was found safe and feasible for adult ADHD patients.

## Abstract

What are the main findings?
The multimodal intervention combining anodal tDCS, digital neurorehabilitation, and psychotherapy showed preliminary clinical improvements in higher-order executive functions, including planning, cognitive flexibility, and visual working memory.Significant clinical reductions in depressive symptoms and measurable enhancements in physical and psychological quality of life domains were observed, suggesting the potential of the protocol for modulating emotional regulation in a clinical setting.

The multimodal intervention combining anodal tDCS, digital neurorehabilitation, and psychotherapy showed preliminary clinical improvements in higher-order executive functions, including planning, cognitive flexibility, and visual working memory.

Significant clinical reductions in depressive symptoms and measurable enhancements in physical and psychological quality of life domains were observed, suggesting the potential of the protocol for modulating emotional regulation in a clinical setting.

What are the implications of the main findings?
Findings suggest a synergistic effect between prefrontal neuromodulation and behavioral interventions, providing a comprehensive framework to address the cognitive–emotional interplay in adult ADHD.The study establishes the safety and feasibility of integrated non-pharmacological protocols, offering a promising evidence-based alternative for adult patients who remain underrepresented in current treatment paradigms.

Findings suggest a synergistic effect between prefrontal neuromodulation and behavioral interventions, providing a comprehensive framework to address the cognitive–emotional interplay in adult ADHD.

The study establishes the safety and feasibility of integrated non-pharmacological protocols, offering a promising evidence-based alternative for adult patients who remain underrepresented in current treatment paradigms.

Background/Objectives: Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorders in childhood and it tends to remain during adulthood. It not only affects cognitive abilities and behavior but also often presents emotional disturbances and alterations in the perceived quality of life. These symptoms are primarily related to dysfunctions in the ventromedial and dorsolateral prefrontal network. The main objective was to evaluate the feasibility and explore the initial outcomes of an integrated protocol combining neuropsychological treatment and transcranial direct current stimulation (tDCS). Methods: This study presents a single-case experimental A-B design of a 21-year-old woman, diagnosed with predominantly inattentive ADHD, treated at the University Psychology Clinic of Loyola Andalucía University. The treatment was carried out twice a week for 5 weeks (10 sessions in total), with 20 min of anodal tDCS at F3 and cathodal tDCS at F4 (2 mA), while digital neurorehabilitation exercises and psychotherapeutic support were provided. Results: An overall significant improvement was observed in cognitive functions (p = 0.008), with clinically significant gains in cognitive flexibility, visual working memory, and planning. Mixed results were found in inhibition, with improvement in interference control but no change in response inhibition. No significant changes were observed in sustained attention, auditory working memory, or processing speed. In terms of emotional state, an overall improvement was noted (p = 0.046), particularly in depression symptoms and perceived quality of life related to physical and psychological health. However, no significant changes were observed in anxiety symptoms or in areas related to the environment and social relationships. These findings reflect pilot-level evidence of clinical change within a feasibility framework. Conclusions: The combined treatment was found to be safe and feasible, showing promising preliminary improvements in cognitive and emotional domains. As a single-case study, these results serve as hypothesis-generating evidence for future controlled trials.