Differentiating neural reward responsiveness in autism versus ADHD

Area of Science:

• Neuroscience
• Developmental Psychology
• Child Psychiatry

Background:

• Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) share overlapping neurocognitive deficits.
• Previous research suggests differentiating ADHD and ASD based on reward responsiveness (social vs. monetary).

Purpose of the Study:

• To investigate neural activation differences in response to social and monetary rewards in boys with ADHD and ASD compared to typically developing controls (TDC).
• To identify distinct and shared neural dysfunction related to reward processing in ADHD and ASD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activation.
• Age and IQ-matched male participants with ADHD, ASD, and TDC were included.
• Participants underwent reward tasks involving social and monetary stimuli.

Main Results:

• A significant interaction effect in the ventral striatum showed TDC preferred monetary over social reward, ADHD responded equally to both, and ASD exhibited low reactivity to both.
• ADHD displayed medial prefrontal hyperactivation to social reward; ASD showed ventral striatal hypoactivation to monetary reward.
• Both ADHD and ASD groups exhibited fronto-striato-parietal hypoactivation during monetary reward anticipation. Lower parietal activation correlated with higher autistic traits.

Conclusions:

• Findings support distinct and shared neural dysfunction in reward processing for ADHD and ASD.
• Reward responsiveness patterns may help differentiate ADHD and ASD.
• Neural abnormalities in reward circuitry are implicated in both ADHD and ASD.