What is the link between dopamine and ADHD?

Attention deficit hyperactivity disorder (ADHD) is a common and chronic neurodevelopmental condition involving symptoms like inattention, hyperactivity, impulsivity, or a combination. It’s most often identified in childhood, but it also impacts a significant number of adults—whether or not they were diagnosed as children.

The Centers for Disease Control and Prevention estimates 8.8 percent of U.S. children have an ADHD diagnosis. CHADD, the National Resource Center for ADHD, estimates around 4.4 percent of adults have ADHD.

While the precise cause and neurological features of ADHD are hard to determine, some studies have shown people with ADHD experience abnormal amounts of the neurotransmitter dopamine in their brains, including difficulty in dopamine transmission. 

This irregularity may cause behavioral and motivational problems that may interfere with an individual's ability to be motivated, achieve goals, and manage behavioral challenges. 

What are neurotransmitters?

Neurotransmitters are chemicals that help carry messages from cell to cell. Their entire job is to take signals from the nerves (also known as neurons) and transport them to the receptors on the target cells, which can be in glands, muscles, or other nerves. Each neurotransmitter has a specific receptor that it “talks” to, making it so they can only activate those specific types of cells. Once they’re finished doing their job, the body “recycles” them so that the process can start all over. 

Think of neurotransmitters and their receptors as a lock and key. The lock will only open when the right key is inserted.

Examples of neurotransmitters include serotonin, norepinephrine, GABA, and dopamine, among others. These neurochemical messengers are responsible for many functions throughout the brain and body, including mood and emotions. 

What is dopamine?

Dopamine is part of our brain's reward system. It's the cause behind the sense of accomplishment you might get when you finish a big project or the sensation you can experience after biting into a chocolate bar. This neurotransmitter is released when your brain interprets stimuli or a situation as rewarding. 

Often called the "pleasure chemical," dopamine is potentially better described as the desire chemical. Dopamine causes the desire to seek out what has previously caused dopamine releases. This function may be beneficial if you seek a reward or a goal that has value to you. For example, stimuli like food or situations like sex and physical activity can cause a release of dopamine in varying amounts. 

Scientists have observed that levels of dopamine are different in people with ADHD than in those without ADHD.

Some researchers believe this difference is because neurons in the brains and nervous systems of people with unmedicated ADHD have higher concentrations of proteins called dopamine transporters. The concentration of these proteins is known as dopamine transporter density (DTD).

A higher DTD results in a lowering of dopamine levels in the brain, which may be a risk factor for ADHD. Just because someone has high levels of DTD, however, doesn’t mean they have ADHD. Doctors will typically use a holistic review to make a formal diagnosis.

What happens when dopamine is low?

Since dopamine plays a role in many important bodily functions, including movement, motivation, reward, learning, and mood, low dopamine levels can cause a variety of symptoms, including:

• Physical symptoms:
  • Fatigue
  • Tremors
  • Slowed movement
  • Muscle stiffness
  • Constipation
  • Difficulty sleeping
• Mental and emotional symptoms:
  • Lack of motivation
  • Difficulty concentrating
  • Decreased pleasure from activities you used to enjoy
  • Depression
  • Anxiety
  • Low sex drive
  • Hallucinations and delusions

How is ADHD treated?

ADHD is treated differently depending on the age and specific needs of each case. The standard approach is a combination of medication and therapy. 

Medications that increase dopamine

Many medications for treating ADHD work by increasing dopamine and stimulating focus. These medications are typically stimulants. They include amphetamines such as:

• amphetamine/dextroamphetamine (Adderall)
• methylphenidate (Concerta, Ritalin)

These medications increase dopamine levels in the brain by targeting dopamine transporters and increasing dopamine levels.

These medications often cause side effects such as low appetite, anxiety, and trouble sleeping, so it's important to work with your doctor to find what's right for you.

Can people with ADHD naturally increase their dopamine levels?

Since medications for ADHD often cause side effects, some people prefer to increase their dopamine levels naturally. Or some may combine medication with alternative methods. Please consult with your healthcare professional about the appropriate ADHD treatment plan for you. Below are some ways one can naturally increase dopamine levels.

Nutrition

Our brain needs certain vitamins, minerals and amino acids to produce neurotransmitters like dopamine. L-Tyrosine is an amino acid found in food like fish, nuts and eggs and plays an important role in the synthesis of dopamine. Supplementing is also a great way to get more L-Tyrosine into your diet.

Exercise

Whether you have hyperactive, inattentive, or combined ADHD, movement is often an essential part of ADHD treatment. Exercise has been shown to increase both dopamine and serotonin production in the brain, as well as increase dopamine receptor density. Even if you don't have the time or inclination to hit the gym, going outside for a walk several times a week may make a difference. 

Meditation

Once considered an alternative treatment, mindfulness meditation is now also recognized for its effect on the ADHD brain. Mindfulness practices involve focusing on the present moment using breathing and deliberate focus techniques. These activities may increase your awareness of your thoughts and emotions and can cause dopamine release for some people. 

They key takeaway is that even though we don’t know precisely how dopamine contributes to ADHD symptoms, we do have very effective medications, alternative methods, and behavioral strategies that can help. If you suspect that you or your child might have ADHD, speak to your health care provider.