How Stimulants Help ADHD

white pills spilled out on table
\. Hero Images/Getty Images

Stimulants are the most common type of medicine used to treat ADHD. They work by increasing the availability of certain chemicals in the brain, thus making the pathways in the brain work more effectively. Stimulants lessen ADHD symptoms in 70 percent to 80 percent of people who take them.

How the Brain Works

Our brains are made up of nerve cells called neurons. These neurons are separated by tiny gaps called synapses. All functions of the brain and nervous system are based on communication among these neurons and across these synapses. The neurons relay information to each other by sending chemical messengers or neurotransmitters across the synapses throughout the neural network.

Neurotransmitters are produced within a neuron. The neuron releases the neurotransmitter and it travels into the synapse space. The neurotransmitter may then be accepted by the next neuron attaching at a site called a receptor, thereby transmitting information from one nerve cell to another throughout the brain.

In order for these pathways to work effectively so that the message gets through, the neuron must produce and release enough of the neurotransmitter. The neurotransmitter must also stay in the synapse space long enough for it to bind to the receptor site.

After the neurotransmitter is released, the excess or unused portion is then recaptured or reabsorbed by the original neuron that produced it. What sometimes seems to happen in individuals with ADHD is the neurotransmitter is prematurely reabsorbed back into the neuron. When this occurs, that portion of the neural network can't relay messages in an adequate and timely way.

How Stimulants Work to Reduce ADHD Symptoms

Stimulants stimulate and increase the release of certain neurotransmitters, most notably dopamine and norepinephrine, and block or slow up how much of these chemicals are being reabsorbed back into the neuron from which they were released. As a result, more of the neurotransmitter is held in the synapse space between neurons long enough for it to properly bind to the receptor, helping messages within the brain be more effectively transmitted and received.

Methylphenidate

Research suggests that methylphenidate (a stimulant that includes the brand name medicines Ritalin, Metadate, and Concerta) primarily blocks the reuptake of dopamine and norepinephrine—that is, slows up how much of the neurotransmitter is being reabsorbed back into the neuron so that more is left in the synapse. And secondarily, methylphenidate seems to facilitate the direct release of neurotransmitter from within the neuron where it's produced and stored, which sends more out into the synapse space.

Amphetamines

Amphetamines (another type of stimulant that includes Vyvanse and Adderall) mostly increase the release of dopamine and norepinephrine from their storage sites into the synapse. A less significant mechanism of amphetamines is slowing the reuptake of the neurotransmitters. The differences in the way these stimulants work may explain why some people with ADHD respond to one type of stimulant medication better than another.

Why Stimulants Help ADHD

Dopamine and norepinephrine seem to play a key role in the areas of the brain responsible for regulating attention and executive function. The reason the stimulants are helpful in reducing symptoms of ADHD appears to be that they make these neurotransmitters more available, therefore improving activity and communication in those parts of the brain which operate on dopamine and norepinephrine and signal for specific tasks.

Brain imaging studies have demonstrated that when you're on stimulant medication, there's evidence of increased metabolic activity in the prefrontal cortex, specific subcortical regions, and the cerebellum—all important centers for executive function. Thus, these areas of the brain appear more active and “turned on” to cognitive tasks when neurotransmitter levels are elevated.

Stimulants don't cure ADHD. What they do is help to alleviate or reduce symptoms while the stimulant is active in your system. Taking stimulants isn't like taking an antibiotic to cure an infection, it's like wearing glasses so you can see, though the glasses don't cure your vision problems.

Was this page helpful?
View Article Sources