Impulsive aggression and response inhibition in attention-deficit/hyperactivity disorder and disruptive behavioral disorders: Findings from a systematic review.
Level 4 - case-series / case-control
Systematic review of observational structural and functional MRI case-control studies.
PubMed 29689282 · doi:10.1016/j.neubiorev.2018.04.016
What was done
The authors conducted a systematic review of structural and functional MRI (s/fMRI) studies in individuals with attention-deficit/hyperactivity disorder (ADHD) and disruptive behavioral disorders (DBDs). The goal was to identify shared and disorder-specific aberrant neural mechanisms associated with impulsive aggression (IA) and response inhibition (RI).
What was found
No quantitative statistics, effect sizes, or participant numbers are reported in the abstract. Qualitatively, ADHD was characterized by prefrontal and cingulate functional alterations and cingulate structural abnormalities associated with IA, while DBDs showed cortico-subcortical dysfunctions. Shared cortico-limbic alterations were identified across both disorders for IA. For RI, ADHD was associated with hypoactivity in the dorsolateral and ventrolateral prefrontal cortex, insula, and striatum, whereas DBDs exhibited primary paralimbic dysfunction.
Why it matters
This synthesis delineates shared cortico-limbic mechanisms for impulsive aggression and distinct prefrontal-striatal versus paralimbic pathways for response inhibition deficits in ADHD and DBDs. These insights help clarify how breakdowns in cognitive-affective control circuits assign improper emotional salience to irrelevant stimuli.
Limits
The abstract omits study selection criteria, total number of reviewed studies, cumulative sample size, demographics, and quantitative meta-analytic pooling. The underlying evidence relies on observational case-control imaging designs, preventing direct causal inference.
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