How Neurotransmitters Are Linked to ADD/ADHD

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Having a better understanding of the relationship between neurotransmitters and the occurrence of ADD/ADHD and its associated symptoms may prove to be beneficial in reducing symptom intensity and treating attention disorders.

A Brief Look at ADD/ADHD

Attention disorders are impressively common in American with nearly 10% of children and upwards of 5% of adults being diagnosed with ADHD. Unfortunately, it appears that the occurrence of ADD/ADHD is increasing significantly. The Centers for Disease Control released a statement showing that the number of cases of ADHD increased annually by 3% between the years of 1997 and 2006.

Each case of ADD/ADHD is highly individualized meaning that one patient may experience symptoms that another does not and at a different levels of intensity. Typically, patients experience an array of symptoms relating to neurological function and mood. Most individuals with ADD/ADHD suffer from at least some of the following symptoms:

  • Aggression
  • Anxiety
  • Boredom
  • Coordination problems
  • Depression
  • Developmental disorder
  • Difficulty focusing
  • Excitability
  • Fidgeting
  • Forgetfulness
  • Impulsivity
  • Irritability
  • Mood swings
  • Poor impulse control
  • Reduced attention span

There are many factors that can contribute to the development of ADD/ADHD symptoms including thyroid dysfunction and heavy metal toxicity. However, many experts agree that neurotransmitters play a critical role in the development of ADD/ADHD.

The Essential Role of Neurotransmitters

The brain is composed of millions of neurons that are concentrated in different locations. These regions are specialized for distinct functions including sensory interaction with the external world and internal system regulation. Responsibilities of these various regions include regulating heart rate, mood, sleep, vision, hearing, and many more.

For the brain, and by extension the rest of the body, to function properly, its various regions must be able to effectively send and receive information. Communication in the brain is made possible through neural circuits composed of neurons and the gaps or synapses between them. Information is carried along these circuits through the use of neurotransmitters.

Scientists have identified at least 50 unique neurotransmitters. It is believed there could be upwards of 200. Neurons produce neurotransmitters to relay specific information through synapses until the original message reaches its intended system. In the presence of abnormal neurotransmitter activity or inappropriate levels, essential messages can be blocked, garbled, or lost. This results in neurological symptoms such as those seen in ADD/ADHD.

Notable Neurotransmitters

Studies show that norepinephrine and dopamine are two of the leading neurotransmitters involved in attention, alertness, effort, and motivation. These substances have been found to act differently in patients with ADD/ADHD when compared to individuals who do not have an attention disorder.


Studies have found that a decrease in dopamine levels in specific areas of the brain promotes the occurrence of various ADD/ADHD symptoms. For example, deficiency of dopamine has been associated with greater occurrence of tangential thoughts, ideas, and behaviors. Furthermore, those with dopamine deficiency are more likely to have an immediate response to situations and be incapable of delaying reaction.

Dopamine is also involved in processes that help maintain a singular thought and analysis of that idea. This is associated with greater ability for decision making, reasoning, and problem solving. Therefore, as dopamine levels decrease in the brain, it is likely that one will have issues with these functions.


Norepinephrine is one of the few neurotransmitters that has been widely accepted as being connected to the development of ADD/ADHD. The responsibilities of this critical neurotransmitter continue to be uncovered. Currently it is believed that norepinephrine plays a role in maintaining mental activity, regulating mood and excitability (particularly in response to danger), and improving memory storage and recollection during stressful periods. It is also understood that norepinephrine influences executive functions such as problem solving, priority setting, and selective attention. Therefore, it should not come as a surprise that deficiency of this critical neurotransmitter often results in ADD/ADHD.

Areas of Disruption

Research shows that neurotransmitter disruption impacts ADHD in four distinct regions of the brain. Many experts believe that neurotransmitter disruption in these systems is at the core of ADHD. Depending on which area is affected, different symptoms and forms of dysfunction are likely to occur. Neurotransmitter defiance in the following regions are associated with the development of ADD/ADHD.

The basal ganglia are made up of neural circuits and act as a sort of switchboard or router of neuronal activity and communication. The basal ganglia direct the flow of information to ensure it reaches the appropriate region of the brain. When this area is lacking neurotransmitters, information can be suddenly halted or lost, which manifests itself as impulsivity and inattentiveness.

The frontal cortex is responsible for high-level functioning including attentiveness, organization, and ability to complete tasks. Neurotransmitter deficiency in the frontal cortex can disrupt each these functions resulting in a worsening of ADD/ADHD symptoms.

The limbic system is a deeply ingrained portion of the brain that regulates emotions. Therefore, poor neurotransmitter representation in this area can trigger restlessness, mood swings, anger, depression, and other forms mood-related symptoms.

The reticular activating system oversees the passage of information in and out of the brain. Neurotransmitter deficiency in this system often results in hyperactivity, impulsivity, and distractedness.

Although these different neurological areas are distinct and separate, they each have significant influence over the others. This means a patient may experience a broad range of ADD/ADHD symptoms even though a single system is the root cause of the malfunction.

Seeking out the Source of ADD/ADHD

ADD/ADHD are common conditions that can have a lifelong effect on quality of life. As diagnosed cases continue to increase, more research is being been done to investigate the primary cause of ADD/ADHD. A promising connection has been made between individual levels of neurotransmitters, specifically norepinephrine and dopamine, in specific regions of the brain and the occurrence of ADD/ADHD and its associated symptoms. Understanding the important role of neurotransmitters in the development of ADD/ADHD may lead to improved treatment and prevention of attention disorders.


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2. Neurotransmitters and ADHD 101. Untapped Brilliance.

3. Neurotransmitters Involved in ADHD. PsychCentral.

4. Attention Deficit Hyperactivity Disorder (ADHD): The Role of Dopamine. Healthline.