What Is Dopamine?

Dopamine is one of the better-known brain chemicals, with lots of attention for its role as a “happy” chemical or relating to addiction. It has numerous important roles beyond that, though, and plays a big part in a host of medical conditions including addiction, schizophrenia, and Parkinson’s disease.

As researchers have uncovered more about brain chemistry and function in general, and about how specific chemicals work, their understanding of this key chemical has grown by leaps and bounds. That means the diagnosis and treatment of dopamine-related conditions are getting better all the time.

What Is Dopamine?

Brain chemicals like dopamine are called neurotransmitters. The word describes their function—they transmit chemical messages between neurons (brain and nerve cells). Outside of your brain, dopamine is a hormone.

Each neurotransmitter has a variety of functions and impacts multiple areas of the brain. They have different jobs in different regions. For example, in the movement centers of the brain, dopamine deals with movement. In the learning areas, though, it deals with attention.

To transmit messages through your nervous system, a neurotransmitter binds to a receptor that’s specifically made for it. It’s like a key slipping into a lock. Dopamine can only interact with neurons that have dopamine receptors.

When a neurotransmitter's function is impaired, it leads to symptoms that are associated with its normal roles. This is called neurotransmitter dysregulation.

You may hear or read about “low levels” or “high levels” of dopamine and other neurotransmitters, but in many cases, experts aren’t sure whether symptoms are caused by:

• Abnormal levels, with producing too much or too little of the neurotransmitter
• Abnormal receptor sensitivity, meaning that the “locks” on neurons aren’t responding properly to dopamine as “key”
• Too few receptors, meaning dopamine can interact with fewer neurons
• Too many receptors, meaning dopamine can interact with more neurons

According to a study published in 2020, the areas of the brain most affected by dopamine appear to be the motor cortex and the insular cortex (also called the insula), but it has widespread influence.

The motor cortex deals with movement. The insular cortex is important for homeostasis, which is how your body maintains a proper temperature, signals that you’re hungry, regulates heartbeat and breathing, and generally keeps things running within proper parameters.

What Dopamine Does

Dopamine is believed to play a role in many important functions in your body, mainly those that deal with mental function, emotional response, and physical reactions.

These include:

• Behaviors involving motivation, punishment, and reward
• Cognitive functions involving attention, learning, and working (short-term) memory
• Voluntary movement
• Pain processing
• Sleep and dreaming
• Mood regulation

While it’s colloquially known as the chemical that makes you happy, it primarily does this in ways that involve reward and motivation.

For example, when you taste your favorite ice cream, you get a dopamine boost and it makes you happy, which gives you the motivation to have another taste. Even anticipating a reward can increase the amount of dopamine activity in your brain.

Low Dopamine

Low dopamine activity can have different physical, cognitive (thinking), and emotional effects. The symptoms of the different conditions vary, depending on the region of the brain where dopamine activity is lacking.

Symptoms of inadequate dopamine activity include:

• Rigid muscles that feel stiff and achy
• Tremors
• Muscle cramps or spasms
• Diminished balance and coordination
• A characteristic gait (walking pattern), often involving small, shuffling steps
• Impairment of fine motor skills (like holding a pencil or threading a needle)
• Constipation
• Difficulty eating and swallowing
• Cognitive impairment (“brain fog”)
• Difficulties with focusing attention
• Fatigue
• Lack of energy
• Slow movement or speech
• Mood swings
• Low sex drive

If you’ve experienced several of these symptoms together, you may not have even realized they could all be related. Be sure to bring up all of your symptoms to your healthcare provider so you can be properly diagnosed and treated.

High Dopamine

High levels of dopamine and excessive dopamine activity in the brain can be debilitating.

High dopamine activity is linked to:

• Anxiety
• Excess energy or mania
• Increased feelings of stress
• High sex drive
• Insomnia
• Aggression
• Hallucinations

Be sure to talk to your healthcare provider if you experience any of these symptoms, especially if you have some of the more serious symptoms, such as hallucinations and aggression.

Related Conditions

A wide array of medical conditions stem from problems with dopamine. Some are considered psychological, while others are classified as physiological, and still others as possibly a mixture of the two. Regardless of how the condition is categorized, it involves very real abnormalities in brain function.

Dopamine-related mental-health conditions include:

• Addiction
• Schizophrenia
• Depression
• Bipolar disorder
• Attention-deficit/hyperactivity disorder
• Obsessive-compulsive disorder
• Binge-eating disorder

Movement disorders involving dopamine include:

• Parkinson’s disease and other parkinsonian syndromes
• Huntington’s disease
• Restless legs syndrome

Some conditions classified as central sensitivity syndromes include dopamine dysregulation, including:

• Fibromyalgia
• Chronic fatigue syndrome

Addiction

Dopamine’s role in reward and motivation is a key aspect of addiction. Whether it’s drugs, food, gambling, shopping, or sex, getting your “fix” gives your brain the good feeling dopamine creates. Your brain can crave that to an unhealthy degree, giving you the motivation to repeat the behavior that leads to the dopamine release.

Technology and Social Media Addiction

A lot of media focus has been given to the idea that technology—especially smartphones and social media—is turning a lot of people into addicts. This is a controversial topic, but some experts say it’s a real threat.

It may be that the constant rewards of social media (e.g., getting “likes” or “shares”) sets up the same cycle of dopamine release and motivation to repeat the behavior that leads to addiction.

In 2019, the Journal of Behavioral Addictions published a study that demonstrated parallels between people with excessive social media use and those with substance abuse and behavioral addictions.

Other Mental/Behavioral Illnesses

Several mental and behavioral illnesses are associated with dopamine dysregulation.

Schizophrenia

Dopamine plays a role in the psychiatric disorder schizophrenia. Other neurotransmitters, including GABA and glutamate, may be important, as well.

Older antipsychotic drugs work by blocking the action of dopamine in the brain, and the fact that they often alleviate symptoms of schizophrenia is strong evidence that dopamine is a culprit. However, some newer antipsychotics also alleviate schizophrenia symptoms without affecting dopamine.

Primary symptoms of schizophrenia include:

• Psychosis (an altered perception of reality)
• Delusions
• Hallucinations
• Disorganized speech and behavior

Major Depressive Disorder (Clinical Depression)

Low activity dopamine has been implicated in some symptoms of major depression, including lack of interest and motivation. The neurotransmitters serotonin and norepinephrine also are believed to be involved in clinical depression, and anti-depressant drugs usually target these two neurotransmitters rather than dopamine.

Bipolar Disorder

Both high and low dopamine activity are theorized to be involved in bipolar disorder, providing a possible explanation of the two phases of the illness: manic (extreme highs) and depressive (extreme lows).

Excess dopamine receptors and a hyperactive reward process network may underly the manic phase of the condition. Meanwhile, decreases in levels of a substance called dopamine transporter may contribute to lower dopamine function and depression. The overall problem may be with neurotransmitter regulation, not simply highs or lows.

Sometimes certain symptoms of bipolar disorder are treated with antipsychotics, which reduce dopamine activity.

Attention Deficit Hyperactivity Disorder (ADHD)

ADHD involves difficulties with attention, working memory, impulsivity, and hyperactive behavior. It’s believed to involve low dopamine activity, possibly due to certain genetic mutations that impact dopamine.

ADHD is often treated with stimulant or antidepressant medications that are theorized to either increase dopamine production in the brain or make more dopamine available to neurons by slowing down certain processes.

Obsessive-Compulsive Disorder (OCD)

Dopamine, along with serotonin and glutamate, is believed to be dysregulated in the anxiety disorder OCD. In OCD, people develop obsessions (intrusive thoughts or images that trigger significant emotional distress) and compulsions (behaviors someone engages in to decrease the upsetting obsessions).

OCD may involve damped dopamine-receptor activity, and also increased dopamine activity in some areas of the brain. Most drug treatments of OCD involve antidepressants, which alter serotonin function but not dopamine.

Binge-Eating Disorder (BED)

BED involves recurrent binging on large amounts of food very quickly, accompanied by feelings of a loss of control and experiences of shame, distress, or guilt. Dopamine dysregulation has been suggested as one possible biological explanation for this condition because it involves impulse control and the reward centers of the brain.

Certain medications that may impact dopamine function are sometimes used to treat BED.

Movement Disorders

Dopamine’s role in the motor cortex of the brain is crucial for your muscles to make smooth, controlled movements. Inadequate dopamine activity in this area is related to several conditions.

Parkinson’s Disease

In Parkinson’s disease, the neurons that create dopamine degenerate, leading to a chronic lack of dopamine.

Resulting symptoms include:

• Tremors
• Stiffness
• Difficulty walking
• Balance problems
• Speech and swallowing issues
• Reduced facial expressions

Parkinson’s is a progressive disease that gets worse over time. It’s treated primarily by drugs that convert to dopamine in the body, increase dopamine levels, or mimic the effects of dopamine.

Huntington’s Disease

Huntington’s disease is a progressive genetic disease that involves both motor and non-motor symptoms. It’s caused by the deterioration of a brain region called the corpus striatum, which is an important part of the motor and reward systems.

Symptoms of Huntington’s include:

• Chorea (a type of uncontrollable movement)
• Cognitive problems
• Poor coordination
• Mood swings
• Problems talking and swallowing

Late in the disease, people can completely lose their ability to walk and talk. Huntington’s can involve symptoms seen in psychiatric disorders tied to excess dopamine activity, including psychosis, aggression, and impulsivity. These symptoms are sometimes treated with atypical antipsychotics.

Restless Leg Syndrome (RLS)

RLS is a movement disorder that involves strange sensations and involuntary leg movements as you sleep or when you’re in a relaxed state. The movements can keep you from getting enough deep sleep and leave you sleep-deprived, even after what would normally be adequate time in bed.

In people with RLS, a few areas of the brain are deficient in iron. In addition, abnormal levels of dopamine in the brain have also been noted. The relationship between low iron and dysregulated dopamine levels isn’t yet understood.

Some research indicates that genetics and hormone abnormalities may also play a role. Many of the medications used to treat RLS are also used in the treatment of Parkinson’s disease.

Central Sensitivity Syndromes

Central sensitivity syndromes include a related group of conditions involving hypersensitivity of the central nervous system, which can include dysregulation of dopamine and other neurotransmitters. These conditions cause abnormal reactions to stimuli.

Fibromyalgia

Fibromyalgia can involve hypersensitivity to pain signals, light, noise, fragrances, temperature, and sometimes certain foods. Research suggests an association with low dopamine activity.

Symptoms of fibromyalgia that may be related to dopamine deficiency include:

• Muscle spasms
• Cognitive dysfunction
• Restless legs syndrome
• Sleep problems
• Anxiety
• Depression
• Mood swings
• Swallowing difficulties

Fibromyalgia isn’t typically treated with medications that directly impact dopamine, as treatment tends to focus more on serotonin and norepinephrine.

Myalgic Encephalomyelitis (ME/CFS)

ME used to be called chronic fatigue syndrome (CFS), and the abbreviations are often combined as ME/CFS or CFS/ME.

It’s a neuroinflammatory disease involving low activity of dopamine, serotonin, and norepinephrine. It features intense fatigue plus extreme sensitivity to exertion and environmental factors (e.g., noise, heat, chemicals).

Symptoms of ME/CFS that may be related to low dopamine activity include:

• Cognitive dysfunction
• Sleep problems
• Anxiety
• Depression
• Mood swings

The treatment of ME/CFS is often aimed at neurotransmitters other than dopamine. However, the ADHD drug methylphenidate is sometimes prescribed off-label for this disease, and it does increase dopamine levels.

Dopamine-Affecting Medications

Several classes of drugs are used to treat conditions involving dopamine dysregulation.

Dopamine Agonists

Dopamine agonists boost dopamine levels or function and are used to treat Parkinson’s disease and RLS.

Examples include:

• Mirapex (pramipexole)
• Requip (ropinirole)
• Neupro (rotigotine patch)

Typical Antipsychotics

Typical antipsychotics lower dopamine activity in the brain by blocking a key dopamine receptor. They’re used to treat schizophrenia and bipolar disorder.

Examples include:

• Thorazine (chlorpromazine)
• Navane (thiothixene)
• Haldol (haloperidol)

Atypical Antipsychotics

Atypical antipsychotics are newer drugs that lower dopamine activity similarly to typical antipsychotics and also affect serotonin. They treat the same conditions as the older typicals, but with fewer side effects.

Examples include:

• Abilify (aripiprazole)
• Seroquel (quetiapine)
• Clozaril (clozapine)