Transcranial direct current stimulation (tDCS): A modern approach to cognitive and emotional enhancement?
By Dr Martine Stoffels, consultant neuropsychiatrist and clinical director, Dr Danny Allen, consultant general adult psychiatrist and clinical director and Jasmin Samuel, director of operations and clinical services, Phoenix Mental Health Services
Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that has gained increasing attention in the fields of neurorehabilitation, psychiatry, and cognitive enhancement.
By delivering a weak electrical current to targeted regions of the brain via electrodes placed on the scalp, tDCS aims to modulate neuronal excitability.
Depending on the electrode placement and polarity, the stimulation can either enhance or inhibit neuronal activity, potentially influencing cognitive, emotional, and motor functions (Nitsche & Paulus, 2000).
The Evolution of tDCS
Though tDCS may seem like a recent innovation, its roots can be traced back to the 19th century, when early researchers experimented with electrical stimulation of the brain.
However, its modern clinical and research applications emerged in the early 2000s, driven by a growing interest in neuromodulation for therapeutic and cognitive purposes (Brunoni et al., 2012).
Over the past two decades, research into tDCS has expanded significantly, with numerous studies investigating its effects on neurological recovery, psychiatric disorders, and cognitive performance.
Boost Mood, Reduce Anxiety, and Enhance Cognitive Function?
One of the most intriguing aspects of tDCS is its potential to improve mood, alleviate anxiety, and enhance cognitive functions such as memory and executive function.
• Mood and Anxiety: Studies have suggested that tDCS targeting the dorsolateral prefrontal cortex (DLPFC) can influence mood regulation.
Some trials indicate that anodal stimulation of this region may reduce symptoms of depression and anxiety, making it a potential non-pharmacological option for mood disorders (Fregni et al., 2006; Razza 2020, Razza 2021, Sobral 2022).
However, results are mixed, and more research is needed to establish definitive protocols.
• Memory and Cognitive Function: tDCS has been explored as a tool to enhance working memory, attention, and problem-solving skills.
Some studies report improved memory performance in both healthy individuals and patients with cognitive impairments, such as those recovering from stroke or brain injury (Boggio et al., 2006).
tDCS in the NHS: Current Status
The NHS has been using tDCS in four NHS trusts across Northamptonshire, Leicestershire, and West London, integrating tDCS into their clinical offerings.
This marks a significant step toward the broader adoption of neuromodulation techniques within public healthcare.
• Preliminary results of a study by the Leicestershire NHS Partnership Trust Crisis Service showed around 80 per cent of patients reported a decrease in their depression symptoms, with some patients experiencing a drop in suicidal ideation by up to 75 per cent, compared to how they reported feeling at the beginning of the pilot.
Data from the pilot programme also found the use of the Flow headsets helped to stabilise patients quickly, with significant improvements in patient mood within two to three weeks.
In addition, one in three patients reported their symptoms had improved so much that they went into remission during the pilot period. The Trust confirmed that hospital admissions had been avoided.
• A study published in the Open Journal of Depression (Griffiths, Walker, & Willis, 2024) explored the experience and value of Flow tDCS in community mental health teams (CMHT).
Among 27 participants, 14 were interviewed, and the results indicated that Flow was feasible, acceptable, and valuable.
Most participants followed the standard protocol and reported positive impacts on depressive symptoms, mood, motivation, and daily functioning.
The study supports integrating Flow as an evidence-backed alternative to traditional depression treatments within CMHT settings.
• Another qualitative study (Griffiths et al., 2024) examined the experience of using Flow tDCS within primary care services for depression treatment.
Participants described improvements in depressive symptoms, sleep, and overall functioning.
The study concluded that integrating tDCS with evidence-based behavioral therapy provides an alternative to antidepressant medication and talking therapies.
These findings support the adoption of Flow as a treatment option for individuals with depression in primary care settings.
• An interpretative phenomenological study (Baukaite et al., 2024) examined the experiences of patients using Flow tDCS within specialist perinatal mental health and maternal loss psychology services.
Participants reported positive experiences with Flow, noting its user-friendly interface, accessibility, and visual instructions.
They appreciated the availability of a non-medication treatment alternative and reported improvements in depressive symptoms, mood, sleep quality, and overall well-being.
The study emphasised the need for personalised approaches to accommodate individual treatment responses and engagement levels.
Can tDCS be a Useful Tool in Neurorehabilitation?
Mental health issues are prevalent among individuals with acquired brain injury (ABI), with high rates of depression and anxiety reported post-injury.
Studies estimate that approximately 30- 60% of ABI survivors experience depression, while anxiety disorders affect around 20-40 per cent (Albanese et al., 2017).
Cognitive changes, including deficits in memory, executive function, and attention, are also common, significantly impacting rehabilitation outcomes.
Research into tDCS as a neurorehabilitation tool suggests that stimulating the prefrontal cortex and motor areas can aid cognitive recovery, improve attention, and support emotional regulation in individuals with brain injuries (Kuo et al., 2014).
Given its non-invasive nature and ease of administration, tDCS holds promise as an adjunctive treatment for cognitive and emotional challenges following ABI.
The challenge in clinical practice for those working within the brain injury field, is to find clinicians who are willing to explore this treatment modality for a group of patients who is usually excluded from research.
Accessing tDCS: Commercial and Clinical Options
One way is to access the treatment, is to purchase a t-DCS device online and use it at home.
This is certainly possible. There are no restrictions on who can buy these devices.
Companies such as Flow Neuroscience offer tDCS devices for purchase online, allowing individuals to use the technology in a home setting under guided protocols.
However, for modified and personalised treatment regimes, patients need to register with a Flow Clinic, which is lead by a consultant psychiatrist.
It is also important to explore if the clinic has inhouse expertise in treating people with brain injury, as this can impact on how the treatment regimes as personalised.
These clinics provide professional oversight, ensuring that tDCS is applied safely and effectively, based on individual patient needs.
The Future of tDCS in Clinical Practice
While tDCS holds promise, its widespread clinical adoption will depend on further high-quality research.
Ethical considerations, accessibility, and long-term safety concerns must also be addressed, although to date no major concerns have been highlighted.
As technology advances and our understanding of neuromodulation deepens, tDCS may emerge as a valuable tool in neurorehabilitation and mental health care, potentially offering a complementary approach alongside traditional therapies.
For now, individuals interested in tDCS should seek professional guidance before attempting any form of self-administration, as improper use could lead to unintended side effects or lack of efficacy.
The coming years will be crucial in determining whether tDCS transitions from an experimental technique to a mainstream therapeutic option within the NHS and beyond.
For access to a Flow clinic with brain injury expertise and experience, contact Phoenix Mental Health services in the UK.
Appendix: References
• Baukaite, E., Noel-Johnson, A., Walker, K., & Griffiths, C. (2024). An interpretative phenomenological study of the experiences and value of Flow transcranial direct current stimulation (tDCS) and behaviour therapy training software used at home for specialist perinatal mental health service and maternal loss psychology service patients with depression. Open Journal of Depression, 13(3).
• Boggio, P. S., Ferrucci, R., Rigonatti, S. P., Covre, P., Nitsche, M., Pascual-Leone, A., & Fregni, F. (2006). Effects of transcranial direct current stimulation on working memory in patients with Parkinson’s disease. Journal of Neurology, Neurosurgery & Psychiatry, 77(1), 112–114.
• Brunoni, A. R., Nitsche, M. A., Bolognini, N., et al. (2012). Clinical research with transcranial direct current stimulation (tDCS): Challenges and future directions. Brain Stimulation, 5(3), 175-195.
• Fregni, F., et al. (2006). A systematic review of the effects of transcranial direct current stimulation on depression. Clinical Neurophysiology, 117(6), 1361-1370.
• Griffiths, C., Walker, K., Jiang, H., Noel-Johnson, A., & Zafar, A. (2024). A qualitative study exploring the experience and value of Flow transcranial direct current stimulation (tDCS) device and behaviour therapy training software application at home for symptoms of depression. Open Journal of Depression, 13(1).
• Griffiths, C., et al (2024). ’Flow’ transcranial direct current stimulation (tDCS) for depression in a Primary Healthcare General Practice -Depression Functioning, and Health related Quality of Life Outocmes. Open Journal of Depression, 13(2).
• Nitsche, M. A., & Paulus, W. (2000). Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation. Journal of Physiology, 527(3), 633–639.
• Razza LB, Palumbo P, Moffa AH, Carvalho AF, Solmi M, Loo CK, Brunoni AR. A systematic review and meta-analysis on the effects of transcranial direct current stimulation in depressive episodes. Depress Anxiety. 2020 Jul;37(7):594-608. doi: 10.1002/da.23004. Epub 2020 Feb 26. PMID: 32101631.
• Razza LB, De Smet S, Moffa A, Sudbrack-Oliveira P, Vanderhasselt MA, Brunoni AR. Follow-up effects of transcranial direct current stimulation (tDCS) for the major depressive episode: A systematic review and meta-analysis. Psychiatry Res. 2021 Aug;302:114024. doi: 10.1016/j.psychres.2021.114024. Epub 2021 May 21. PMID: 34058716.
• Sobral M, Guiomar R, Martins V, Ganho-Ávila A. Home-based transcranial direct current stimulation in dual active treatments for symptoms of depression and anxiety: A case series. Front Psychiatry. 2022 Oct 6;13:947435. doi: 10.3389/fpsyt.2022.947435. PMID: 36276322; PMCID: PMC9583668.
