Dopamine is one of the best-known brain chemicals, with much emphasis on its role as a "lucky" or addiction-related chemical. However, it has many important functions beyond this and plays an important role in a variety of diseases, including drug addiction, schizophrenia, and Parkinson's disease .
As researchers have learned more about the chemistry and functions of the brain in general, and how certain chemicals work, their understanding of this key chemical has exploded. This means that the diagnosis and treatment of dopamine-related conditions is continually improving.
What is dopamine?
Chemicals in the brain, such as dopamine, are called neurotransmitters. This 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 multiple functions and affects various areas of the brain. They have different jobs in different regions. For example, in the motor centers of the brain, dopamine is responsible for movement. However, in the field of teaching, it is all about care.
To transmit messages through your nervous system, a neurotransmitter "binds" to a receptor specially designed for it. It is like a key in a lock. Dopamine can only interact with neurons that have dopamine receptors.
When the function of a neurotransmitter is impaired, symptoms associated with its normal function occur. 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 are not sure if symptoms are caused by:
- Abnormal level, as if the brain is producing too much. or very little
- Abnormal receptor sensitivity, which means that "locked" neurons do not respond adequately to dopamine as a "key."
- There are very few receptors, which means that dopamine can interact with fewer neurons.
- There are too many receptors, which means that dopamine can interact with more neurons.
According to a study published in 2020, the areas of the brain most affected by dopamine are the motor cortex and the insular cortex (also called the islet), but it has widespread effects.
The motor cortex is responsible for movement. The insular cortex is important for homeostasis, which is how your body maintains proper temperature, indicates you're hungry, regulates your heart rate and breathing, and generally keeps you working properly.
Relationship with norepinephrine
Dopamine is closely related to the neurotransmitter norepinephrine. Your body makes norepinephrine from dopamine, it appears to bind to the same receptors, and they work together to perform many functions. Research shows that they can even be produced and released by the same cells.
What does dopamine do?
Dopamine is believed to play a role in many important functions in your body, primarily those related to mental functions and emotional and physical responses.
These include :
- Behavior that involves motivation, punishment, and reward.
- Cognitive functions related to attention, learning and working memory (short term)
- Voluntary movement
- Pain treatment
- Dream and dreams
- Mood setting
Although it's colloquially known as the chemical that makes you happy, it really only does so in ways that involve reward and motivation.
For example, when you try your favorite ice cream, it increases your dopamine levels, which makes you happy, which gives you the motivation to try another flavor. Even waiting for a reward can increase dopamine activity in your brain .
Low dopamine levels
Symptoms of low dopamine activity can affect many areas of your health and life. They differ based on the area of the brain that lacks dopamine or dopamine activity.
Symptoms of dopamine deficiency include:
- Stiff muscles that feel stiff and painful
- Muscle cramps or spasms
- Imbalance and coordination problems
- Distinctive gait (gait), often involving small, dragging steps
- Fine motor skills (such as holding a pencil or threading a needle)
- Eating and swallowing problems.
- Cognitive impairment ("brain fog")
- Difficulty focusing attention
- Lack of energy
- Slow motion or speak
- Humor changes
- Low sex drive
If you've experienced several of these symptoms together, you may not even have known that they could all be related. Make sure to tell your doctor about all of your symptoms so that they can be diagnosed and treated correctly.
High dopamine levels and excessive dopamine activity in the brain can be debilitating, but some of the symptoms can be viewed as positive, especially when it comes to learning.
High dopamine activity is associated with:
- Excess energy or mania
- Increased feeling of stress.
- Improve attention and learning capacity.
- High sex drive
Be sure to speak with your doctor if you experience any of these symptoms, especially if you have some of the more serious symptoms, such as hallucinations and aggression.
Dopamine's effect on learning has led some high school and college students to take dopamine-increasing drugs in hopes of improving their exams. Healthcare professionals advise against this practice due to its many potentially dangerous side effects.
A wide range of diseases arise from dopamine problems. Some of these are considered psychological, some are physiological, and some are possibly a mix of the two. Regardless of how this condition is classified, it is associated with very real brain dysfunctions.
Dopamine-related mental health conditions include:
- Bipolar disorder
- Hyperactive disorder and attention deficit
- Obsessive compulsive disorder
- Compulsive overeating
Dopamine-related movement disorders include:
- Parkinson's disease
- huntington's disease
- Restless Leg Syndrome
Several conditions classified as central sensitivity syndromes involve dopamine dysregulation, including:
- Chronic Fatigue Syndrome
The role of dopamine in reward and motivation is a key aspect of addiction. Whether it's drugs , food, gambling, shopping, or sex, getting the "drug" gives your brain the good feeling that dopamine does. Your brain may crave it to an unhealthy degree, giving you the motivation to repeat the behavior that triggers the release of dopamine.
Technology and social media addiction
There has been a lot of media attention to the idea that technology, especially smartphones and social media, is making many people addicted. This is a controversial topic, but some experts believe that it is a real threat.
It is possible that the constant rewards of social media (such as getting "likes" or "forwards") trigger the same cycle of dopamine release and motivation to repeat behaviors that lead to addiction.
In 2019, the journal Behavioral Addictions published a study that showed parallels between people who abuse social media and people with substance abuse and behavioral addictions .
Other mental / behavioral illnesses
Several mental and behavioral illnesses are associated with dopamine dysregulation.
Dopamine plays a role in the mental disorder schizophrenia . Other neurotransmitters, including GABA and glutamate, can also play a role.
Older antipsychotic drugs work by blocking the action of dopamine in the brain, and the fact that they often relieve the symptoms of schizophrenia is strong evidence that dopamine is the culprit. However, some newer antipsychotics also relieve symptoms of schizophrenia without affecting dopamine.
The main symptoms of schizophrenia include:
- Psychosis (altered perception of reality)
- Disorganized speech and behavior
Major depressive disorder (clinical depression)
Low dopamine activity is associated with several symptoms of major depression , including a lack of interest and motivation. The neurotransmitters serotonin and norepinephrine are also believed to be involved in clinical depression, and antidepressants generally target these two neurotransmitters rather than dopamine.
It is suggested that both high and low dopamine activity are associated with bipolar disorder , providing a possible explanation for the two phases of the illness: manic (extreme highs and lows) and depressive (extreme lows).
An overabundance of dopamine receptors and an overactive reward system may underlie the manic phase of the condition. Meanwhile, lowering the levels of a substance called the dopamine transporter can contribute to decreased dopamine function and depression. A common problem may be related to dopamine regulation, rather than just increasing or decreasing levels.
Sometimes some of the symptoms of bipolar disorder are treated with antipsychotics that decrease dopamine activity.
Attention deficit hyperactivity disorder (ADHD)
ADHD includes problems with attention, working memory, impulsivity, and hyperactive behavior. This is believed to be due to low dopamine activity, possibly due to certain genetic mutations that affect dopamine.
ADHD is often treated with stimulants or antidepressants that, in theory, increase dopamine production in the brain or make neurons have more dopamine by slowing down certain processes.
Obsessive compulsive disorder (OCD)
Dopamine, along with serotonin and glutamate, is believed to interfere with the regulation of anxiety disorder in OCD . In OCD, people develop obsessions (obsessions or images that cause significant emotional stress) and compulsions (behaviors that someone uses to reduce bothersome obsessions).
OCD may involve suppression of dopamine receptor activity, as well as increased dopamine activity in certain areas of the brain. Most drug treatments for OCD use antidepressants that alter the function of serotonin, but not dopamine.
Binge eating disorder (BED)
BED involves the repetitive and very rapid ingestion of large amounts of food, accompanied by feelings of loss of control and feelings of shame, anguish or guilt. It has been suggested that dopamine dysregulation is a possible biological explanation for this condition, as it involves impulse control and reward centers in the brain.
Sometimes certain medications that can interfere with dopamine function are used to treat binge eating disorder.
The role of dopamine in the motor cortex is essential for the muscles to perform smooth and controlled movements. Insufficient dopamine activity in this area is associated with several conditions.
In Parkinson's disease , dopamine-producing neurons degenerate, resulting in chronic dopamine deficiency.
As a result, the following symptoms appear :
- Dificulty to walk
- Balance problems
- Trouble speaking and swallowing
- Reduce facial expressions
Parkinson's disease is a progressive disease that gets worse over time. It is primarily treated with drugs that convert to dopamine in the body, increase dopamine levels, or mimic the effects of dopamine.
Huntington's disease is a progressive genetic disorder that presents with motor and non-motor symptoms. It is caused by damage to an area of the brain called the striatum, which is an important part of the motor and reward systems.
Huntington's symptoms include:
- Uncontrolled movements
- Cognitive problems
- Poor coordination
- Humor changes
- Trouble speaking and swallowing
In the later stages of the disease, people can completely lose the ability to walk and speak. Huntington's disease can include symptoms of mental disorders associated with excess dopamine activity, such as psychosis , aggressiveness, and impulsivity. Sometimes these symptoms are treated with atypical antipsychotics.
Restless legs syndrome (RLS)
RLS is a movement disorder in which strange sensations and involuntary leg spasms occur during sleep or in a relaxed state. Movement can keep you from getting enough sleep and deprive you of sleep, even after you usually have enough time in bed.
In people with RLS, some areas of the brain are iron deficient. Also, abnormal levels of dopamine have been observed in the brain. The link between low iron and high dopamine content has not yet been studied, and researchers don't understand why these factors cause RLS symptoms.
However, some research suggests that genetic and hormonal abnormalities may play a role as well. Many medications used to treat RLS are also used to treat Parkinson's disease.
Central sensitivity syndromes
Central sensitivity syndrome is an umbrella term for a related group of conditions involving central nervous system hypersensitivity, which can include dysregulation of dopamine and other neurotransmitters. These conditions elicit abnormal responses to stimuli.
Fibromyalgia symptoms that may be associated with a dopamine deficiency include:
Myalgic encephalomyelitis (ME / CFS)
ME was previously called chronic fatigue syndrome (CFS), and the acronyms are often combined as ME / CFS or CFS / ME.
It is a neuro-inflammatory disorder associated with low levels of dopamine, serotonin, and norepinephrine. You are very fatigued and extremely sensitive to physical stress and environmental factors (eg noise, heat , chemicals).
Symptoms of ME / CFS that may be associated with low dopamine activity include:
- Cognitive dysfunction
- Trouble sleeping
- Humor changes
As with fibromyalgia, ME / CFS treatments often target other neurotransmitters in addition to dopamine. However, methylphenidate for ADHD is sometimes used incorrectly to treat ADHD and increases dopamine levels .
Medications that affect dopamine
Several classes of medications are used to treat conditions associated with dopamine dysregulation.
Dopamine agonists increase dopamine levels or function and are used to treat Parkinson's disease and RLS.
Typical antipsychotics reduce dopamine activity in the brain by blocking a key dopamine receptor. They are used to treat schizophrenia and bipolar disorder.
- Thorazine (chlorpromazine)
- Navane (thiothixene)
- Haldol (haloperidol)
Atypical antipsychotics are new drugs that reduce dopamine activity in a similar way to typical antipsychotics and also affect serotonin. They treat the same conditions as typical older medications, but with fewer side effects.
- Abilify (aripiprazole)
- Quetiapine (quetiapine)
- Clozaril (clozapine)