Differences between Autism spectrum disorders and attention-deficit/hyperactivity disorder in brain function: A resting-state fMRI research.

Scientists used brain scans to study differences between autism and ADHD, looking at 115 people including those with autism, ADHD, and typical development. They found that autistic people had different brain activity patterns in areas involved in attention and social processing, while people with ADHD didn't show clear differences from typical controls. The study suggests autism and ADHD have different underlying brain mechanisms, which could help with diagnosis and treatment planning in the future.

This neuroimaging study compared brain function patterns between autism spectrum disorder (ASD) and ADHD using resting-state fMRI in 115 participants across four groups. Researchers measured amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) to identify disorder-specific neural signatures. ASD participants showed significantly elevated brain activity in the anterior cingulate gyrus and right precentral gyrus compared to controls, while ADHD participants showed no significant differences from their controls. Direct comparisons revealed distinct patterns: ASD had increased activity in the right precentral gyrus and decreased activity in the left fusiform gyrus, plus elevated synchronization in the right middle occipital gyrus.

These findings suggest different underlying neural mechanisms between the conditions.

Findings suggest distinct neural patterns between ASD and ADHD that may eventually support differential diagnosis. However, translation to clinical practice requires validation in larger, more diverse samples and development of standardized protocols before implementation in diagnostic frameworks.

Sample sizes were relatively small (28-30 per group). Study type was not specified, limiting assessment of methodology quality. The abstract doesn't report participant characteristics, medication status, or control for potential confounders that could influence brain imaging results.

The clinical distinction between ASD and ADHD poses significant diagnostic challenges due to their symptomatic similarities. To address this issue, we systematically examined functional brain differences between these disorders. By combining amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) resting-state fMRI metrics, this study provides a more robust neurofunctional characterization of ASD and ADHD. Using resting-state fMRI, we compared ALFF and ReHo among four groups: 28 ASD-only participants, 29 typically developing controls matched to ASD participants (TD(ASD)), 28 ADHD-only participants, 30 typically developing controls matched to ADHD participants (TD(ADHD)).

These analyses quantified region-specific neural activity intensity and local synchronization to identify disorder-specific functional patterns. Compared to TD(ASD) controls, the ASD group exhibited significantly elevated ALFF and ReHo in the anterior cingulate gyrus (ACG) and right precentral gyrus (PreCG) (p < 0.05, GRF-corrected). In contrast, no significant differences were observed between ADHD and TD(ADHD) groups. Direct ASD-ADHD comparisons revealed: Increased ALFF in the right PreCG and decreased ALFF in the left fusiform gyrus (FG); Elevated ReHo in the right middle occipital gyrus (MOG) in ASD (p < 0.05, GRF-corrected).

The distinct ALFF and ReHo patterns observed between ASD and ADHD provide compelling neurobiological evidence for their divergent neural mechanisms. These disorder-specific functional signatures, particularly in the anterior cingulate and occipito-frontal circuits, may guide future neuromodulation research and eventually contribute to refining differential diagnostic frameworks in clinical practice.