Brain Function 101- why medicine helps those with ADHD
Updated: Apr 3
There’s a commonly held belief that people with ADHD should just try harder, but this doesn’t usually work. The symptoms of ADHD are caused in part by imbalances of neurotransmitters in the brain. Low norepinephrine levels lead to symptoms of ADHD. More and more evidence is showing the differences in the brains of people with ADHD compared to neurotypical (“normal”) people.
ADHD is real. You can’t just will it away.
What if no meds are used for ADHD?
Not everyone with ADHD is treated with medication. There are many reasons.
Some have never been diagnosed. Others don’t like medicine for whatever reason.
Many teens want to come off their medications. Some don’t like side effects. Others don’t want to be different.
Some people simply forget to take it and then struggle with the consequences of being unmedicated.
Many families have a hard time affording the medicine or taking the time to do the required follow up with their physician.
I’m sure there are many more reasons people stop (or never start) medicine.
Before discussing how the medicines work, it’s important to learn about neurotransmitters.
Our brain is of course very complicated in structure and function. There are millions of neurons that make up our brains. Between each neuron is a synapse, or space. Different areas of the brain serve different functions, and they all interact with each other. They also interact with other parts of our body and the outside world.
There are many pathways or circuits that bring information from one part of our brain to another. Neurotransmitters are the messengers that bring information from one neuron to another. They are made from amino acids.
Neurotransmitters each have a unique function but can be broadly classified into two categories: excitatory and inhibitory. Some neurotransmitters can serve both functions.
Excitatory neurotransmitters regulate motor movement, thought processes, anxiety, and more.
They can help us stay alert, but when they aren’t moderated by an inhibitory system, things can get out of control.
Inhibitory neurotransmitters act like brakes.
We need brakes so we don’t feel restless, irritable, and out of focus. When our brakes work, we can excel! Without brakes, we’re out of control.
Lock and key
Neurotransmitters act as messengers between different neurons. They are released from one neuron into the space between neurons called the synapse. They enter a neuron that has the proper shaped structure for it to fit.
It works like a lock and key.
Each neurotransmitter is like a different key. They each fit certain locks, and often can fit more than one type of lock.
Neurotransmitter levels and ADHD
When neurotransmitter levels are too high or too low, we can develop anxiety, depression, and executive functioning disruptions.
It is important to understand that to some extent we can control our actions, but neurotransmitters are important in the aspects that are beyond our control. Sometimes we just feel anxious or sad. Focusing can be very difficult. Executive functions, such as time management, working memory, and more, can be hard to manage.
Norepinephrine is an excitatory neurotransmitter. It is primarily made and stored in neurons but is also found in the blood and a small amount is stored in the adrenal glands, which sit on top of our kidneys.
Norepinephrine is involved in focus, emotions, sleeping, dreaming, and learning. Too much norepinephrine can cause anxiety, but too little can lead to problems with focus and motivation.
It can raise our heart rate, increase blood flow to muscles, and increase our blood sugar level – all symptoms we experience in times of anxiety. These are helpful responses when stress is caused by physical danger and we need to run away, but not so much when we worry about a test or other common anxieties.
These symptoms can lead to distraction, self-consciousness, and poor focus and performance. This can look a lot like when norepinephrine levels are too low, which is one reason why anxiety and ADHD can mimic one another as well as exacerbate one another.
Dopamine makes us feel happy. Getting a bump in dopamine feels good.
I often joke that we get a dopamine hit every time we check social media or win a game. One of the reasons depressed people overeat comfort foods is that eating rises our dopamine levels, which makes us feel better. (At least until the heartburn sets in or we notice we’ve gained a few too many pounds to be healthy.)
Dopamine is one of the neurotransmitters that can be both excitatory and inhibitory.
Drugs like nicotine (yes, even from electronic cigarettes), opiates, and alcohol all increase dopamine levels. Eating foods can have the same dopamine increase, as can winning a game or doing anything else pleasurable.
We can all choose healthy options to get dopamine hits. Exercise. Playing games. Enjoying the company of friends and family. Helping others. All of these are healthy things that bring us happiness.
Negative things, such as drugs and alcohol or too much screen time, can lead to more problems than they’re worth. Even though they bring temporary feelings of happiness, they cause more problems in the end. Avoid these dopamine hits.
Dopamine can increase our alertness and help with memory and motor control in addition to giving us pleasure.
Dopamine can be converted into norepinephrine and epinephrine.
Low levels of dopamine are associated with problems focusing, depression, the inclination to abuse drugs and alcohol, excessively playing games online or gambling , and overeating.
If the levels are low in motor areas of the brain, it can lead to the tremors commonly seen in Parkinson’s disease.
Low levels in other parts of the brain can lead to learning and memory problems, lack of energy and motivation, and a loss of happiness and interest in things that used to bring pleasure.
Low levels in the prefrontal cortex are associated with ADHD.
High levels of dopamine can cause overexcitement and disrupted thoughts. They can even lead to anxiety and paranoia.
Serotonin is important in the regulation of anger and aggression, body temperature, mood, sleep, sexuality, appetite and metabolism. It can help us relax when serotonin is available in proper amounts. Stress can lower our serotonin levels as we use it up trying to relax.
About 80-90% of the body’s total serotonin is found in the gut. It is made by bacteria that live in our gastrointestinal tract. There are ongoing studies using probiotics (healthy bacteria) to alter the level of serotonin to help anxiety and depression. Unfortunately, as of now studies show mixed results, and at best only a minor benefit.
Low levels of serotonin can result in depression, anxiety, anger, panic attacks, low energy, migraines, insomnia, obsessions, irritability, craving sweets or loss of appetite, focus and memory problems, aggressive behavior, slowed muscle movement and speech, and having a decreased interest in sex.
High levels of serotonin cause diarrhea, headache, confusion, sweatiness, twitching muscles or stiff muscles, fever, high heart rate and blood pressure, seizures, and even death.
How do ADHD medicines work?
Stimulant medicines are considered the first line medical treatment for ADHD. The two types of stimulants are methylphenidates and amphetamines.
The differences in how these two groups of stimulant types work may explain why some people with ADHD respond to one type better than another.
Methylphenidates include prescription medicines such as Ritalin, Metadate, Concerta, Focalin, Aptensio, Quillivant and others.
The methylphenidates block the reuptake of dopamine and norepinephrine. This leaves more of these neurotransmitters in the synapse. Methylphenidates also help release these neurotransmitters from the neuron, again allowing more to be in the synapse.
Amphetamines include Adderall and Vyvanse. They increase the release of dopamine and norepinephrine from their storage sites into the synapse. They also slow the reuptake of the neurotransmitters, but not to a large extent.
How do medicines affect neurotransmitters?
Medicines that affect neurotransmitters are used to treat ADHD, anxiety, depression, and low blood pressure.
Stimulant medicines (methylphenidates and amphetamines) increase norepinephrine and dopamine.
Atomoxetine (Strattera) affects only norepinephrine.
Serotonin norepinephrine reuptake inhibitors (SNRIs) are antidepressants that work by increasing serotonin and norepinephrine.
Tricyclic antidepressants also increase norepinephrine and serotonin, but are not often used anymore since there are many safer options available.
Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat anxiety and depression. They block the reabsorption of serotonin, which leaves more available in the synapse.
MAOIs prevent the breakdown of serotonin (and other neurotransmitters) but are rarely used due to significant adverse reactions.
In addition to the resources hyperlinked throughout this post, check out the following:
For more on the basics of the medicines used to treat ADHD, see ADHD Medications: Types and side effects.
Did you know that while stimulants that are used to treat ADHD can help people with ADHD, they can cause imbalances to neurotransmitters to those without ADHD? Learn how stimulants can make focus, attention, mood and more worse in Stimulants decrease brain function. Say What?