Understanding ADHD, the Brain, and Medication
This post is for teachers, parents, students, and ADHDers.
I want to be transparent from the start: I have never taken ADHD medication myself, and I have never been formally diagnosed with ADHD. A few years ago, during a therapy session, my therapist asked if I had ADHD. I said I had dyslexia, and at the time I had never even considered ADHD as a possibility.
I’ve linked my sources at the end of this post, so if you want to dig deeper, please do.
To begin, we’ll answer a few key questions and then bring everything together.
What Is the Prefrontal Cortex (PFC)?
The prefrontal cortex (PFC) sits just behind the forehead. It plays a major role in regulating attention, behaviour, and internal awareness.
Some of its key functions include:
External awareness
Managing internal dialogue (“What am I thinking about right now?”)
Paying attention to environmental sounds and distractions
Remembering tasks and responsibilities
Working memory (holding information in mind while using it)
Internal bodily awareness
Noticing hunger or fatigue
Awareness of physical comfort or discomfort (for example, sitting still in a chair)
What Roles Do Dopamine and Adrenaline Play?
Dopamine is a neurotransmitter (a chemical messenger in the brain). It helps regulate:
Movement
Memory
Motivation and reward
Behaviour and cognition
Attention
Sleep and arousal
Mood
Learning
Adrenaline is both a hormone and a neurotransmitter. It’s part of the sympathetic nervous system, commonly known as the “fight or flight” response. It plays a role in:
Metabolism
Alertness
Focus
Panic and anxiety responses
Excitement
How Are Messages Sent in the Brain?
The brain communicates through a complex network of neurons. Between each neuron is a small gap called a synapse, where chemical messages are exchanged.
Neurotransmitters (like dopamine and adrenaline) are released from one neuron (the presynaptic cell) and received by the next (the postsynaptic cell).
After release, neurotransporter proteins reabsorb some of these neurotransmitters back into the presynaptic cell. There are specific transporters for dopamine and for adrenaline.
What Is the PFC Like in an ADHD Brain?
The PFC’s job is to regulate and coordinate activity across different areas of the brain, turning some regions up and others down when needed.
In ADHD, the issue is not a deficit or damage to the PFC. Instead, it’s a difficulty with coordination and communication between the PFC and other brain networks. The brain may be under-connected or over-connected in certain pathways.
An Example: The Default Mode Network (DMN)
The default mode network (DMN) is involved in imagination, daydreaming, and internal thoughts. It’s active most of the time.
When we need to focus, the PFC normally “dials down” the DMN. However, in many people with ADHD, the DMN stays highly active even during tasks that require concentration. This can make focusing feel extremely difficult.
How Do ADHD Medications Affect These Signals?
This is a high-level overview, I’ll go into specific medications in a later post.
Dopamine and adrenaline work together to regulate attention and focus. When something happens, the PFC decides how much attention is needed and sends signals to other parts of the brain (for example, telling the DMN to quiet down).
In ADHD, these messages may not be received clearly. One reason is an imbalance in neurotransmitter activity at the synapse.
Neurotransporter proteins can:
Reabsorb dopamine, reducing how much is passed between neurons
Reabsorb adrenaline, reducing its availability
Medication can influence how active these transporters are. Over time, this changes how much dopamine and adrenaline are released during signalling, helping the brain rebalance attention and focus.
A Simplified Example
If someone struggles to concentrate and frequently daydreams, medication may help increase focus. At the synapse, the medication can shift how dopamine and adrenaline are distributed, reducing activity in networks like the DMN and supporting areas involved in concentration.
In this sense, stimulant medication “stimulates” the system by changing how neurotransmitters are caught, released, and reused.
Stimulant vs Non-Stimulant Medication
Around 80% of people with ADHD are prescribed stimulant medication.
The remaining 20% use non-stimulant medication, which primarily targets adrenaline rather than dopamine.
Key Takeaways
ADHD medication works by influencing the balance and collaboration between dopamine and adrenaline
An ADHD brain is not deficient, it is differently connected
The PFC has difficulty communicating clearly with other brain networks
Neurotransmission is, quite literally, a game of catch
Medication affects how neurotransmitters are caught and reused at the synapse
In the next post, we’ll look at specific ADHD medications and how they work.
Fun Fact (…not really)
Around 80% of university students report using ADHD medication to help them concentrate during exams, even without a diagnosis.
Is this a good idea? We’ll come back to that.
