KEY STRUCTURAL DIFFERENCES

Prefrontal Cortex

The prefrontal cortex supports executive functions such as attention regulation, decision-making, and impulse control. In individuals with ADHD, this area may show differences in size and activity, which can contribute to challenges with focus, planning, and self-regulation.

Basal Ganglia

The basal ganglia play an important role in regulating movement, behavior, and motivation. Research suggests that reduced volume in this region may be associated with symptoms such as impulsivity, hyperactivity, and difficulty sustaining attention in individuals with ADHD.

Cerebellum

The cerebellum is involved in coordination, timing, and certain aspects of attention. Structural differences in the cerebellum seen in some individuals with ADHD may influence motor control, focus, and task consistency.

Corpus Callosum

The corpus callosum connects the brain’s left and right hemispheres, allowing effective communication between regions. Variations in thickness or development in individuals with ADHD may affect how efficiently information is shared across the brain.

KEY FUNCTIONAL DIFFERENCES

Beyond physical or structural variations, research indicates that ADHD can influence how certain brain systems function—especially those involved in attention, emotional regulation, impulse control, and how rewards are processed. These functional patterns often show up in brain-imaging and EEG studies and help clarify why daily tasks may feel harder for individuals with ADHD.

Attention

People with ADHD often find it challenging to maintain steady focus, particularly during tasks that require sustained mental effort. Distractions may pull their attention more easily. In contrast, individuals without ADHD usually display more consistent attention and can stay engaged with fewer interruptions.

Impulse Control

Many individuals with ADHD struggle with pausing before reacting or fully considering the consequences of an action. This can lead to quicker, more impulsive responses. Those without ADHD typically have stronger internal braking systems and may take more time to weigh decisions.

Emotional Regulation

Emotional reactions can be more intense or harder to dial down for people with ADHD. Differences in the brain networks that support emotional self-management may make it difficult to reset after feeling upset or overwhelmed. Individuals without ADHD generally experience more even emotional responses and can regain composure more easily.

Reward Processing

Studies suggest that ADHD may influence how the brain responds to rewards. This can create a stronger pull toward immediate payoff and make it harder to stay motivated for longer-term rewards or delayed outcomes. People without ADHD tend to show a more gradual reward response, supporting patience and sustained effort.

Brain Activity

Neuroimaging research has found that individuals with ADHD may show reduced activation in areas linked to planning, attention control, and impulse regulation. These activity patterns can help explain real-world challenges with organization, follow-through, and staying on task.

Brain Waves

EEG findings often show increased slow-wave activity (such as theta waves) in the prefrontal regions of the brain in individuals with ADHD. Higher levels of these slow waves are associated with difficulties organizing thoughts, maintaining attention, and making decisions. People without ADHD typically display more balanced brain-wave patterns during tasks requiring focus.

Source: Empower Recovery / April 3, 2025