Systematic Review: Medication Effects on Brain Intrinsic Functional Connectivity in Patients With...

Area of Science:

• Neuroscience
• Pharmacology
• Radiology

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder.
• Medication is a primary treatment for ADHD, but its neural mechanisms are not fully understood.
• Resting-state functional magnetic resonance imaging (R-fMRI) offers insights into brain function.

Purpose of the Study:

• To systematically review and summarize within-subject R-fMRI studies on medication-induced changes in ADHD patients.
• To critically appraise the strengths and limitations of existing research.
• To provide recommendations for future studies in this field.

Main Methods:

• Systematic review of published English-language studies up to July 1, 2020.
• Inclusion of pediatric and adult patients diagnosed with ADHD.
• Assessment of study design, reporting, and methodological quality.

Main Results:

• Nine studies (5 pediatric, 4 adult) were reviewed, with small to medium sample sizes and limited female representation.
• Heterogeneity in study designs, analyses, and results prevented quantitative synthesis.
• While some brain regions showed medication-related changes, a unified mechanistic hypothesis was not supported, and reproducibility standards were not met.

Conclusions:

• Emerging R-fMRI research suggests potential modulatory effects of ADHD medications (stimulants, atomoxetine) on intrinsic brain activity.
• Significant methodological heterogeneity and reporting deficiencies hinder validation of findings.
• Future research must address these limitations to advance understanding and potential clinical application of R-fMRI in ADHD treatment.