Without dopamine, we wouldn’t be able to feel driven and motivated. Dopamine increases attention, improves cognitive function, and stimulates our creativity. It makes us more social and extroverted and helps us form romantic and parental bonds. However, dopamine, when too high, can also have its drawbacks. Many people seek out artificial sources of dopamine, which can lead to addiction. Read on to learn more about dopamine, genetics included.
What is Dopamine?
Dopamine is a neurotransmitter, which is a chemical released by neurons (nerve cells) to send signals to other nerve cells .
Many areas of the brain produce dopamine. It is produced in the ventral tegmental area (VTA in the image above) of the midbrain, the substantia nigra pars compacta, and the arcuate nucleus of the hypothalamus .
The most important dopamine pathway in the brain controls reward-motivated behavior .
Most types of rewards, such as new experiences or accomplishments, can increase dopamine levels in the brain. In addition, most addictive drugs and behavioral addictions can increase dopamine .
Dysfunctions of the dopamine system contribute to Parkinson’s disease, schizophrenia, restless legs syndrome, and attention-deficit hyperactivity disorder (ADHD) .
Schizophrenia is characterized by high striatum dopamine, but abnormally low prefrontal dopamine activity .
Genetics Behind Dopamine
- Dopamine D1 Receptor gene (DRD1)
- Dopamine D2 Receptor gene (DRD2) 
- Dopamine D3 Receptor gene (DRD3)
- Dopamine D4 Receptor gene (DRD4) 
- Dopamine D5 Receptor gene (DRD5)
- Tyrosine Hydroxylase (TH)
- Dopamine beta-hydroxylase (DBH)
- Catechol-O-Methyltransferase (COMT)
- D-amino acid oxidase (DAO)
- DOPA decarboxylase (DDC)
- Monoamine oxidase A (MAOA)
- Monoamine oxidase B (MAOB)
- Vesicular monoamine transporter 2 (VMAT2)
There are no symptoms associated with low dopamine levels per se. Instead, people with “dopamine deficiency” may only show symptoms of mental health or neurocognitive disorders. Your doctor will discuss your results with you. They may run additional tests to pinpoint the underlying cause of your low levels.
Low or high dopamine levels don’t necessarily indicate a problem if there are no symptoms or if your doctor tells you not to worry about it.
- Depression and other mental disorders
- Attention disorders (such as ADHD)
- Parkinson’s Disease
- Low Motivation
- Weight gain
- Increased Appetite
- Low Libido
- Higher prolactin
- Anhedonia (lack of pleasure)
- Memory Problems
- “Brain Fog”
- Introverted personality
- Lowered ability to form romantic attachments
Dopamine Health Effects
Please note: diverse roles of dopamine as a neurotransmitter and hormone don’t necessarily imply any potential benefits of exogenous (outside) sources of dopamine in treatment or supplementation.
1) Responsible for Motivation
In animal experiments, high, moderate and low concentrations of dopamine induce euphoric, seeking and aversive states, respectively .
Across different mammalian species, there is a linkage between dopamine and the positive experiences associated with exploration, new learning and interest in one’s environment .
On the other hand, low levels of dopamine make people and animals less likely to work for things. Dopamine blockade severely impairs effortful actions to obtain rewards .
Mutant mice that do not synthesize dopamine die of starvation owing to a lack of motivation to eat. Restoring neurotransmission in the striatum rescues these animals, whereas restoring it in the nucleus accumbens does not .
2) Increases the Anticipation of Pleasure
When exposed to a rewarding stimulus, the brain responds by releasing more dopamine .
During these pleasurable situations, dopamine is released and stimulates one to seek out the pleasurable activity .
Pleasurable experiences such as sex, food, games or even drug abuse can increase dopamine release .
This brain reward system promotes survival of the species by rewarding behaviors necessary for continued survival such as seeking food, reproduction, shelter, and drink, etc. These activities that are essential to species survival and activate this pathway are associated with ‘feeling good’ .
Histamine, acting on histamine H1 receptors, can potentiate dopamine receptors to become more sensitive to dopamine . Therefore, people with higher histamine levels or stronger H1 receptor activation may feel more pleasure from dopamine.
Dopamine does not mediate pleasure. It is known that the loss of dopamine does not affect the feeling of pleasure in humans or animals .
What it does is enhances the expectation of pleasure in humans .
3) Helps with Memory and Learning
Dopamine activity in the brain plays a big part in memory and learning . It is essential for long-term memory storage and retrieval.
Dopamine signals important events. It helps you remember events that have motivational significance. This ensures that memories are relevant and accessible for future behavior .
Dopamine also plays an essential role in working memory. Working memory is the capacity to use information from short-term memory and use it to guide your own actions. Dopamine promotes nerve cell activity involved in working memory .
Serotonin also works with dopamine during memory formation. Activation of serotonin receptors can increase dopamine release in parts of the brain that are involved in cognition and memory formation, i.e. the prefrontal cortex and hippocampus) (28).
Dopamine release causes an individual to be motivated by certain stimuli. It can control and teach the individual different behaviors. Thus, it plays an important part in reward-driven learning .
4) Increases Attention and Focus
Dopamine has a role in focus and attention .
Dopamine dysfunction in frontal lobes can cause a decline in attention or even attention deficit disorders .
Moderate levels of dopamine (not too high or too low) improve the capacity of individuals to switch attention efficiently between tasks. Furthermore, moderate levels of dopamine direct attention more efficiently to stimuli that are relevant to ongoing tasks [31, 32].
5) Makes People More Social and Extroverted
Dopamine and its pathways are generally associated with more extroverted behavior .
For example, higher dopamine levels in 16 male patients were associated with a more extroverted personality .
There are several major dopamine-related genes that may affect how many dopamine receptors a person has, which in turn can influence the overall activity of the brain’s dopamine system.
For example, according to several studies, people who carry a ‘C’ allele for the DRD4 SNP rs1800955 show higher levels of extraversion and novelty-seeking [35, 36]. This DRD4 genotype is associated with a greater number of D4 dopamine receptors, and therefore may result in higher dopamine activity — but the available research is limited, and more studies will be needed to fully confirm this finding.
According to another study, carriers of the ‘A’ allele for the DRD2 SNP rs1800497 have up to one-third fewer D2 dopamine receptors . However, unlike several other types of dopamine receptors, D2 receptors are inhibitory. This suggests that people with this DRD2 variant actually have higher overall dopamine activity levels (since their dopamine neurons are less inhibited by D2 receptors) [38, 39, 40]. Consequently, carriers of this allele were also reported to have significantly higher scores on trait extroversion, which fits in with what we know about these receptors .
(P.S.: If you’d like to know more about the DRD2 gene and its effects on the brain, we recommend checking out the SelfDecode blog post on DRD2.)
6) Important for Love (Romantic Attachments)
Intense romantic love is associated with the dopamine reward system. Dopamine is released through sex, touch, and orgasm, and plays a major role in the formation and maintenance of pair bonds [41, 42, 43].
When human subjects viewed photographs of people with whom they were in love, their brain activity patterns looked remarkably similar to those observed after cocaine infusions, or monetary reward, with heavy activation of dopamine-rich regions in the brain [44, 45, 46, 42].
Prairie voles mate for life. However, injecting prairie voles with dopamine blockers causes them to lose their monogamous tendencies – they fail to show any partner preference .
7) Helps Establish Maternal Behavior
Maternal behavior is the result of a highly-motivated brain, that allows the female to flexibly adapt her caring activities to different situations .
Increases in dopamine levels are observed during nursing bouts .
Injections of dopamine receptor blockers result in deficits in maternal behavior in rats. On the other hand, improvements in dopaminergic signaling positively impact the deficits observed in maternal behaviors .
8) May Decrease Inflammation Due to Th1 and Th17 Dominance
Dopamine is shown to interact with the immune system. Treatment with dopamine can decrease inflammation and have other therapeutic effects .
The Dopamine 3 (D3) and D5 receptors are more inflammatory, while the D1, D2, and D4 receptors are more anti-inflammatory .
Low levels of dopamine would stimulate mainly the D3 receptor in T cells, favoring Th1-like responses and T cell activity. Moderate dopamine levels would stimulate the Dopamine D5 receptor as well, inhibiting T cell function. All of these increase inflammation .
Overall, higher dopamine levels decrease T cell response and inflammation .
DRD1 signaling inhibits the NLRP3 inflammasome. Inflammasomes are immune system receptors and sensors that induce inflammation in response to infectious microbes. DRD1 activation can potentially treat NLRP3-driven inflammation and diseases .
9) Influences the Sleep Cycle
Dopamine and its receptors play a part in controlling the sleep-wake cycle. Mainly, dopamine can help keep you awake and alert .
On the other hand, mice depleted of dopamine have a complete suppression of REM sleep. Activating dopamine receptors helped recover REM sleep. This indicates that dopamine is vital in regulating sleep .
DRD2 activation causes different effects depending on the levels of activation. Low levels of activation reduce wakefulness and increase Slow Wave (deep) and REM sleep. On the other hand, high DRD2 levels induce the opposite effect .
Compounds that block both D1 and D2 receptors reduce wakefulness and increase deep sleep .
Patients suffering from Parkinson’s disease may also have sleep disturbances because they have low dopamine .
10) Helps Increase Bone Strength
Additionally, some male patients with excess levels of prolactin due to low dopamine can have a low bone mineral density (BMD). Dopamine treatment increased their BMD and strengthened their bones .
Also, dopamine treatment increased bone cell formation and mineralization in mouse cell culture .
11) Increases Creativity
Studies show that human creativity relies on dopamine. However, creativity is complex, and different aspects of creativity are affected by different dopaminergic systems .
A study shows that Parkinson’s disease patients treated with dopaminergic drugs show enhanced verbal and visual creativity .
Dopamine is involved in cognitive flexibility – one of the main components of creativity and creative thinking. Dopamine is also responsible for the openness to new experiences, another factor associated with creativity .
In healthy people, creativity was positively correlated with gray matter in dopamine-rich regions of the brain .
A polymorphism in DRD4 has a complex relationship with creativity. DRD4-7R is associated with impaired flexibility associated with low creativity. On the other hand, according to preliminary research, this allele is associated with higher novelty-seeking associated with greater flexibility and creativity .
12) Speeds up Our Internal Clock
Our sense of time is far from constant. For instance, time flies when we are having fun, and it slows to a trickle when we are bored .
The ‘internal clock’, is abnormally slow in Parkinson’s disease .
13) Relieves Nausea
The stomach and intestines also have dopamine receptors. Dopamine acts through specific receptors to lower pressure in the gut. Drugs that increase dopamine activity stimulate the intestines to increase movement and function .
These drugs can help relieve nausea, vomiting, and even acid reflux .
Drugs that block the DRD2 receptor can decrease nausea, perhaps by increasing dopamine activity.
14) Inhibits Prolactin
It is important for prolactin hormone levels to be balanced. High prolactin levels (hyperprolactinemia) can cause reproductive problems in both men and women. Therefore, dopamine may help “fine-tune” the brain’s overall levels of prolactin .
15) Helps Movement
The basal ganglia, which is one of the largest and most important dopamine-based systems in the brain, is highly involved in controlling movement (among many other diverse functions). In order for the basal ganglia to function well, it requires sufficient dopamine release at the input nuclei .
Relatedly, it is believed that the loss of dopamine neurons in the basal ganglia is what is primarily responsible for the movement problems often seen in Parkinson’s patients, such as tremors and rigidity .
16) Helps Prevent Parkinson’s Disease
Dopamine is responsible for the communication between two regions in the brain, which is the substantia nigra and the corpus striatum. This is critical in producing smooth, purposeful movement. Loss of dopamine in this circuit results in impaired movement.
The nerve cells in this circuit produce dopamine. Parkinson’s disease occurs when these nerve cells become impaired and/or die.
When approximately 60 to 80% of the dopamine-producing cells are damaged and do not produce enough dopamine, the motor symptoms of Parkinson’s disease appear .
Low dopamine levels contribute to the painful symptoms that frequently occur in Parkinson’s disease .
17) Helps Prevent Nearsightedness (Myopia)
The biggest risk for nearsightedness in people is the amount of time spent indoors .
Scientists can induce myopia in animals by lowering the level of light .
The leading hypothesis is that light stimulates the release of dopamine in the retina, and this, in turn, blocks the elongation of the eye during development .
Injecting a dopamine-inhibiting drug called spiperone into chicks’ eyes could abolish the protective effect of bright light .
Retinal dopamine is normally ramped up during the day, which helps daytime vision. Researchers now suspect that under dim (typically indoor) lighting, the cycle is disrupted, and this leads to myopia .
18) Stimulates Sexual Drive
A person’s response to sex, just like other rewards, is largely dependent on dopamine (particularly the “mesolimbic” pathway) .
Dopamine (in the reward system and hypothalamus) plays a central role in sexual arousal, sexual motivation and penile erections .
Erections are dependent upon activation of both dopaminergic neurons (in the ventral tegmental area, or “VTA”) and dopamine receptors (in the nucleus accumbens) .
Some of the effects of dopamine on sexual behavior may be due to dopamine’s ability to decrease prolactin, a hormone that can inhibit sexual drive (particularly in men) .
Cons of Excessive Dopamine
Dopamine levels are a marker of mental health. Low or high dopamine levels don’t necessarily indicate a problem if there are no symptoms or if your doctor tells you not to worry about it.
1) Plays a Role in Schizophrenia
Schizophrenia is characterized by negative symptoms such as apathy and poor social functioning, and positive symptoms, such as hallucinations and delusions .
The dopamine hypothesis proposes that schizophrenia is caused by excessive production of dopamine in the brain .
Studies support the idea that an overactive dopamine system may result in schizophrenia. Medications that block dopamine receptors, specifically D2 receptors, reduce schizophrenia symptoms .
Additionally, some evidence suggests that the negative symptoms and some of the cognitive deficits in schizophrenia may be related to lower prefrontal cortex function. This, in turn, may be associated with decreased dopamine activity. However, there is only indirect evidence to support this .
Thus, some features of negative schizophrenia (social withdrawal, apathy, and the inability to feel pleasure) are thought to be related to low dopamine levels in certain areas of the brain .
2) Can Drive Drug Addiction
The reinforcing effects of these drugs don’t only come about because of increased dopamine, but also because of the fast rate that dopamine increases. The faster the increase, the more intense the reinforcing effects . This can reduce (“down-regulate”) the dopamine receptors over a period of time, causing increased need (“cravings”) for the drugs, as well as many other chronic problems.
Long-term drug use seems to be associated with decreased dopamine function. The reductions in D2 dopamine receptors and dopamine release in the striatum in addicted subjects supports this hypothesis .
3) Involved in Porn Addiction (and Other Behavioral Addictions)
Dopamine may contribute to compulsive sexual behaviors .
Both sexual experience and drugs act through dopamine D1 receptors (nucleus accumbens) .
Sexual novelty is compelling because it triggers bursts of dopamine in regions of the brain strongly associated with reward and goal-directed behavior. However, compulsive internet pornography users show a stronger preference for novel sexual images. Also, they get used to them more rapidly, which fuels the search for more novel sexual images .
In Parkinson’s disease, dopamine replacement therapies (levodopa, dopamine agonists) have been associated with compulsive sexual behavior and other impulse-control disorders . Some patients reported uncharacteristic compulsive pornography use and had greater brain activity in response to sexual pictures, correlating with enhanced sexual desire .
Is porn addiction a problem? Some link porn to the increase in sexual performance problems and low sexual desire in men under 40. When a porn user has linked his sexual arousal to internet pornography, sex with desired real partners may register as “not meeting expectations”, resulting in a corresponding decline in dopamine, and erectile problems .
It is important to consider this question: are we, as a society, becoming “dopamine junkies”?
A lot of people today may succumb to “pleasure-maximizing choice behavior”. Some argue that we may be turning ourselves into mindless pleasure junkies, looking for the next dopamine shoot .
Basically, our choice behavior becomes biased towards short-term pleasure-maximizing goals, just as in the addicted brain and away from long-term prosperity and general well-being maximizing objectives .
4) Affects Weight
It is associated with the desire to eat the food and with the conditioning of food cues. It is also involved with the motivation to perform the behaviors necessary to buy, prepare, and consume the food .
So, dopamine will cause you to desire food when you simply smell it. It causes you to ‘want’ food as opposed to just ‘liking’ the food .
Because dopamine is released when someone eats food, this could contribute to overeating. They will seek to increase their dopamine levels with food consumption which can cause weight gain and obesity , especially in people with low dopamine levels.
Dopamine is also associated with the motivation to alleviate negative emotions through eating. In both normal-weight and obese participants, emotional eating was associated with higher dopamine receptor D2R binding .
5) May Cause Aggression
High levels of dopamine can cause aggression. Blocking dopamine receptors decreases aggression in some people .
6) Decreases Empathy and Cooperation
Some observe that our modern society is a dopaminergic society. It is an extremely goal-oriented, fast-paced, and even manic society. Dopamine is known to increase activity levels, speed up our internal clocks, and create a preference for novel environments over unchanging ones .
On the other hand, high-dopamine individuals lack empathy and exhibit a more masculine behavioral style: conquest, competition, and aggression over nurturance and communality .
In a different study, people with the COMT 158Val variant, resulting in lower dopamine levels, showed higher cooperation compared to 158Met people with higher dopamine. Carriers of two 158Val variants (lower dopamine) are considered to be more helpful and empathic .
7) Can Cause Constipation
Dopaminergic medications in Parkinson’s disease can increase constipation risk .