No abstract

The stimulant methylphenidate (MPX) and the nonstimulant atomoxetine (ATX) are the most commonly prescribed medications for attention deficit hyperactivity disorder (ADHD). However, no functional magnetic resonance imaging (fMRI) study has as yet investigated the effects of ATX on inhibitory or any other brain function in ADHD patients or compared its effects with those of MPX. A randomized, double-blind, placebo-controlled, crossover pharmacological design was used to compare the neurofunctional effects of single doses of MPX, ATX, and placebo during a stop task, combined with fMRI within 19 medication-naive ADHD boys, and their potential normalization effects relative to 29 age-matched healthy boys. Compared with controls, ADHD boys under placebo showed bilateral ventrolateral prefrontal, middle temporal, and cerebellar underactivation. Within patients, MPX relative to ATX and placebo significantly upregulated right ventrolateral prefrontal activation, which correlated with enhanced inhibitory capacity. Relative to controls, both drugs significantly normalized the left ventrolateral prefrontal underactivation observed under placebo, while MPX had a drug-specific effect of normalizing right ventrolateral prefrontal and cerebellar underactivation observed under both placebo and ATX. The findings show shared and drug-specific effects of MPX and ATX on performance and brain activation during inhibitory control in ADHD patients with superior upregulation and normalization effects of MPX.

The results suggest that fMRI signal decreases are possible correlates of emotion suppression in depersonalisation disorder.

Background: Overgeneralised self-blame and worthlessness are key symptoms of major depressive disorder (MDD) and were previously associated with self-blame-selective changes in connectivity between right superior anterior temporal lobe (rSATL) and subgenual frontal areas. In a previous study, remitted MDD patients successfully modulated guilt-selective rSATL-subgenual cingulate connectivity using real-time functional magnetic resonance imaging (rtfMRI) neurofeedback training, thereby increasing their self-esteem. The feasibility and potential of using this approach in symptomatic MDD were unknown. Methods: This single-blind pre-registered randomised controlled pilot trial tested the clinical potential of a novel self-guided psychological intervention with and without additional rSATL-posterior subgenual cortex (SC) rtfMRI neurofeedback, targeting self-blaming emotions in insufficiently recovered people with MDD and early treatment-resistance (n=43, n=35 completers). Following a diagnostic baseline assessment, patients completed three self-guided sessions to rebalance self-blaming biases and a post-treatment assessment. The fMRI neurofeedback software FRIEND was used to measure rSATL-posterior SC connectivity, while the BDI-II was administered to assess depressive symptom severity as a primary outcome measure. Results: Both interventions were demonstrated to be safe and beneficial, resulting in a mean reduction of MDD symptom severity by 46% and response rates of more than 55%, with no group difference. Secondary analyses, however, revealed a differential response on our primary outcome measure between MDD patients with and without DSM-5 defined anxious distress. Stratifying by anxious distress features was investigated, because this was found to be the most common subtype in our sample. MDD patients without anxious distress showed a higher response to rtfMRI neurofeedback training compared to the psychological intervention, with the opposite pattern found in anxious MDD. We explored potentially confounding clinical differences between subgroups and found that anxious MDD patients were much more likely to experience anger towards others as measured on our psychopathological interview which might play a role in their poorer response to neurofeedback. In keeping with the hypothesis that self-worth plays a key role in MDD, improvement on our primary outcome measure was correlated with increases in self-esteem after the intervention and this correlated with the frequency with which participants employed the strategies to tackle self-blame outside of the treatment sessions. Conclusions: These findings suggest that self-blame-selective rtfMRI neurofeedback training may be superior over a solely psychological intervention in non-anxious MDD, although further confirmatory studies are needed. The self-guided psychological intervention showed a surprisingly high clinical potential in the anxious MDD group which needs further confirmation compared vs treatment-as-usual. Future studies need to investigate whether self-blame-selective rSATL-SC connectivity changes are irrelevant in anxious MDD, which could explain their response being better to the psychological intervention without interfering neurofeedback.

The identification of meaningful functional magnetic resonance imaging (fMRI) biomarkers requires measures that reliably capture brain performance across different subjects and over multiple scanning sessions. Recent developments in fMRI acquisition, such as the introduction of multiband (MB) protocols and in‐plane acceleration, allow for increased scanning speed and improved temporal resolution. However, they may also lead to reduced temporal signal to noise ratio and increased signal leakage between simultaneously excited slices. These methods have been adopted in several scanning modalities including diffusion weighted imaging and fMRI. To our knowledge, no study has formally compared the reliability of the same resting‐state fMRI (rs‐fMRI) metrics (amplitude of low‐frequency fluctuations; seed‐to‐voxel and region of interest [ROI]‐to‐ROI connectivity) across conventional single‐band fMRI and different MB acquisitions, with and without in‐plane acceleration, across three sessions. In this study, 24 healthy older adults were scanned over three visits, on weeks 0, 1, and 4, and, on each occasion, underwent a conventional single band rs‐fMRI scan and three different rs‐fMRI scans with MB factors 4 and 6, with and without in‐plane acceleration. Across all three rs‐fMRI metrics, the reliability scores were highest with MB factor 4 with no in‐plane acceleration for cortical areas and with conventional single band for subcortical areas. Recommendations for future research studies are discussed.