P300 Modulation via Transcranial Alternating Current Stimulation in Adult Attention-Deficit/Hyperactivity Disorder: A Crossover Study

ObjectiveA repeated finding regarding event-related potentials (ERPs) is that patients with ADHD show a reduced P300 amplitude. This raises the question of whether the attention of ADHD patients can be increased by stabilizing the P300. Assuming that the P300 is generated by event-related oscillations (EROs) in the low frequency range (0–8 Hz), one approach to increase the P300 could be to stimulate the patient’s P300 underlying ERO by means of transcranial alternating current stimulation (tACS). The aim of this follow-up study was to investigate this hypothesized mechanism of action in adult ADHD patients.Materials and MethodsUndergoing a crossover design, 20 adult ADHD patients (10 female) received an actual stimulation via tACS on one day and a sham stimulation on another day. Before and after each intervention, EEG characteristics (P300 amplitudes, low frequency power) and attention performances (d2 attention test, visual oddball task (VOT)) were recorded.ResultsElectrophysiological analyses revealed no evidence for an enhanced P300 amplitude or low frequency power increase after actual stimulation compared to sham stimulation. Instead, a significant effect was found for a stronger N700 amplitude increase after actual stimulation compared to sham stimulation. Consistent with the P300 null results, none of the examined neuropsychological performance measures indicated a tACS-induced improvement in attentional ability.ConclusionContrary to a previous study using tACS to modulate the P300 in adult ADHD patients, the current study yields no evidence that tACS can increase the P300 amplitude in adult ADHD patients and that such P300 enhancement can directly improve neuropsychological parameters of attention

Smartphone-assisted Psychoeducation in Adult Attention-Deficit/Hyperactivity Disorder: A Randomized Controlled Trial

Psychoeducation is generally recommended in the treatment of adult Attention-Deficit/Hyperactivity Disorder (ADHD), but only few studies have systematically assessed the effects of structured clinical psychoeducation. Moreover, although a considerable number of psychoeducational mobile applications exist, none have provided scientific evidence for their effectiveness or safety. Therefore, the present randomized controlled trial investigated a newly developed, free-to-use psychoeducation app for adults with ADHD as a support to a clinical psychoeducation group. 236 adults with ADHD were contacted for study participation, of whom 60 were finally randomized to a psychoeducation group supported either by our developed smartphone app (n = 30) or by traditional pen-and-paper brochures (n = 30). Psychoeducation treatments were conducted in groups of 10, with 8 weekly one-hour sessions between March 2019 and November 2020. Observer-rated ADHD symptom severity (IDA-R interview) was examined as the primary outcome parameter before and after treatment. Across both interventions, ADHD core symptoms were significantly reduced. Notably, the smartphone-assisted psychoeducation was significantly more effective in improving inattention and impulsivity and led to higher homework compliance than the brochure-assisted psychoeducation. No adverse events were reported