Functional Imaging Changes in the Medial Prefrontal Cortex in Adult ADHD

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Childhood ADHD studies show reduced frontal activity and default mode network (DMN) de-activation.
• Research on neural bases of executive function in adult ADHD is limited and inconclusive.

Purpose of the Study:

• Investigate neural correlates of executive function in adult ADHD using fMRI during the N-back task.
• Explore the impact of long-term methylphenidate treatment on brain activity in adult ADHD.

Main Methods:

• Recruited adult ADHD participants and matched controls for fMRI scanning during a 2-back task.
• Subdivided ADHD group into treatment-naive and long-term methylphenidate users (medication washed out).

Main Results:

• Adult ADHD participants exhibited deficient de-activation in the medial prefrontal cortex during the 2-back task.
• This indicates potential default mode network dysfunction in adult ADHD.
• No correlation was found between de-activation deficits and methylphenidate treatment history.

Conclusions:

• Failure to deactivate the medial frontal cortex is associated with attention lapses.
• Findings suggest a link between DMN dysfunction and ADHD symptomatology in adults.