A pilot meta-analysis on self-reported efficacy of neurofeedback for adolescents and adults with ADHD

Gaze-based attention refocusing training in virtual reality for adult attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is characterized by substantial interindividual heterogeneity that challenges the systematic assessment and treatment. Considering mixed evidence from previous neurofeedback research, we present a novel feedback system that relies on gaze behavior to detect signs of inattention while performing a neuropsychological attention task in a virtual seminar room. More specifically, an audiovisual feedback was given whenever participants averted their gaze from the given task.

METHODS

Eighteen adults with ADHD and 18 healthy controls performed a continuous performance task (CPT) in virtual reality under three counterbalanced conditions in which either gaze-based feedback, sham feedback, or no feedback was provided. In all conditions, phases of high and low virtual distraction alternated. CPT errors and reaction times, proportions of gaze dwell times (e.g., task focus or distraction focus), saccade characteristics, EEG theta/beta ratios, head movements, and an experience sampling of ADHD symptoms were analyzed.

RESULTS

While patients can be discriminated well from healthy controls in that they showed more omission errors, higher reaction times, higher distraction-related dwell times, and more head movements, the feedback did not immediately improve task performance. It was also indicated that sham feedback was rather associated with an aggravation of symptoms in patients.

CONCLUSIONS

Our findings demonstrate sufficient suitability and specificity for this holistic ADHD symptom assessment. Regarding the feedback, a single-session training was insufficient to achieve learning effects based on the proposed metacognitive strategies. Future longitudinal, multi-session trials should conclusively examine the therapeutic efficacy of gaze-based virtual reality attention training in ADHD.

TRIAL REGISTRATION

drks.de (identifier: DRKS00022370).

Additive effects of EEG neurofeedback on medications for ADHD: a systematic review and meta-analysis

To elucidate possible additive effects of electroencephalogram-based neurofeedback (EEG-NF) on medications against the core symptoms of attention-deficit/hyperactivity disorder (ADHD), randomized controlled trials (RCTs) were retrieved from electronic databases including PubMed, EMBASE, ClinicalKey, Cochrane CENTRAL, ScienceDirect, and ClinicalTrials.gov from inception to March 2022. The primary outcomes were changes in ADHD symptoms (i.e., global, inattention, hyperactivity/impulsivity) assessed with validated rating scales, while secondary outcome was all-cause discontinuation rate. Meta-analysis of five RCTs involving 305 participants [Median age = 9.285 years (range 8.6-11.05)] with a median follow-up of 12 weeks showed additive effects of EEG-NF on medications from parents' observations against ADHD global symptoms (Hedges' g = 0.2898, 95%CI [0.0238; 0.5557]) and inattention symptoms (Hedges' g = 0.3274, 95%CI [0.0493; 0.6055]). However, additive effects failed to sustain six months after EEG-NF intervention. Besides, there was no difference in improvement of hyperactivity/impulsivity from parents' observation, attentional performance, and all-cause discontinuation rate between the two groups. Our results supported additional benefits of combining EEG-NF with medications compared to medication alone in treating global symptoms and symptoms of inattention in ADHD patients. Nevertheless, given a lack of evidence showing a correlation between underlying physiological changes and small effect sizes in our preliminary results, further studies are warranted to support our findings.

Impact of prior bariatric surgery on risk and severity of COVID-19 infection: A meta-analysis of observational studies

BACKGROUND

The association of prior bariatric surgery (BS) with infection rate and prognosis of coronavirus disease 2019 (COVID-19) remains unclear. We conducted a meta-analysis of observational studies to address this issue.

METHODS

We searched databases including MEDLINE, Embase, and CENTRAL from inception to May, 2022. The primary outcome was risk of mortality, while secondary outcomes included risk of hospital/intensive care unit (ICU) admission, mechanical ventilation, acute kidney injury (AKI), and infection rate.

RESULTS

Eleven studies involving 151,475 patients were analyzed. Meta-analysis showed lower risks of mortality [odd ratio (OR)= 0.42, 95% CI: 0.27-0.65, p < 0.001, I² = 67%; nine studies; 151,113 patients, certainty of evidence (COE):moderate], hospital admission (OR=0.56, 95% CI: 0.36-0.85, p = 0.007, I² =74.6%; seven studies; 17,810 patients; COE:low), ICU admission (OR=0.5, 95% CI: 0.37-0.67, p < 0.001, I² =0%; six studies; 17,496 patients, COE:moderate), mechanical ventilation (OR=0.52, 95% CI: 0.37-0.72, p < 0.001, I² =57.1%; seven studies; 137,992 patients, COE:moderate) in patients with prior BS (BS group) than those with obesity without surgical treatment (non-BS group). There was no difference in risk of AKI (OR=0.74, 95% CI: 0.41-1.32, p = 0.304, I² =83.6%; four studies; 129,562 patients, COE: very low) and infection rate (OR=1.05, 95% CI: 0.89-1.22, p = 0.572, I² =0%; four studies; 12,633 patients, COE:low) between the two groups. Subgroup analysis from matched cohort studies demonstrated associations of prior BS with lower risks of mortality, ICU admission, mechanical ventilation, and AKI.

CONCLUSION

Our results showed a correlation between prior BS and less severe COVID-19, which warrants further investigations to verify.