Overall symptoms of children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are not significantly alleviated with high-definition transcranial direct current stimulation (HD-tDCS). However, there may be significant improvements in the cognitive measures of attention maintenance, according to the results of a study published in Frontiers in Psychiatry.
Researchers evaluated the impact of treatment with HD-tDCS of the right orbital frontal cortex (OFC) on clinical symptoms, impulse control, and emotion processing among children and adolescents with ADHD.
They recruited children and adolescents (aged 8 to 18 years) with ADHD who visited the general outpatient department and the children’s outpatient department of the Zhenjiang Mental Health Center (The Fifth People’s Hospital of Zhenjiang City) in China between March 2020 and November 2021.
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A total of 56 patients with ADHD were randomly assigned to either the HD-tDCS group (n=28; 10 girls, 14 boys; 11.29±2.51 years of age) or the sham group (n=28; 10 girls, 13 boys; 11.74±2.59 years of age), 47 of whom completed each session and evaluation. All children were right-handed and of Chinese Han origin.
Exclusion criteria included metal device implants; skull defects; intracranial hypertension; history of brain trauma, epilepsy, or other serious neurologic, circulatory, endocrine, or other physical diseases; audio-visual impairments; color blindness; color weakness; narrow-angle glaucoma; recent treatment with ADHD medication; and history of any other brain stimulation.
No significant differences were reported between the 2 groups in sex, age, educational years, total IQ, course of disease, age of onset, whether they came from a single-parent family, and ADHD type (P >.05).
A 1.0-mA anode current was applied to the right OFC of participants in the HD-tDCS group and the sham group received sham stimulation for 10 sessions.
Cognitive effect was evaluated by the Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), the Stroop Color and Word Test (Stroop), and the Tower of Hanoi (TOH) test. ADHD symptom assessment (the SNAP-IV Rating Scale and the Perceived Stress Questionnaire [PSQ]) was performed before treatment, after the fifth and tenth stimuli, and at the sixth week after the end of all stimulation.
The researchers reported that the mean visual and auditory reaction times by IVA-CPT, the interference reaction time of Stroop Color and Word, the number of completed steps of the TOH test, SNAP-IV score, and PSQ score did not change with intervention time before and after treatment (P <.0031). They noted that compared with the sham group after the fifth intervention, tenth intervention, and the sixth week of intervention follow-up, the integrated visual and audiovisual commission errors and the TOH test completion time results of the HD-tDCS group were significantly decreased.
The goal of the TOH test is to move stacked disks one at a time from a starting position to a target position, arranged in a pyramid form on the target position without ever placing a larger disk on top of a smaller disk. The time of accomplishment of the TOH test improved but the number of steps required for accomplishment did not improve. The researchers suggested that real tDCS improves attention maintenance, and participants need to increase sustained attention to complete tasks without distraction.
Significant study limitations include but are not limited to its underpowered sample size, impatience of participants during stimulation, lack of age stratification, and inability to distinguish treatment effects among different ADHD subtypes.
The researchers stated that their study “draws cautious conclusions that HD-tDCS does not significantly alleviate the overall symptoms of patients with ADHD but leads to significant improvements in the cognitive measures of attention maintenance.” However, they caution that “tDCS cannot be recommended as an alternative neurotherapy for ADHD yet.”
Reference
Wang YC, Liu J, Wu YC, et al. 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. Published online February 13, 2023. doi:10.3389/fpsyt.2023.987093
This article originally appeared on Psychiatry Advisor
