Dopamine is a neurotransmitter that plays a crucial role in pleasure and reward. It is a chemical messenger which is involved in physiological and neurological functioning. It is also related to certain psychiatric and movement disorders.
What Is Dopamine?
The neurotransmitter dopamine (DA) is produced in the brain and serves various important functions in our brain and body. Although it is produced in our brain, the neurotransmitter is mainly used by the nervous system to transmit messages to nerve cells. It primarily acts as a chemical messenger connecting neurons and is usually released when expecting a reward. “Dopamine (DA) is the most abundant catecholaminergic neurotransmitter in the mammalian brain, and is involved in incentive-motivational pathways as well as in response to aversive stimuli,” explains a 2018 research 1. It also plays an important role in mood, decision making and motor function.
DA is not only strongly associated with the sensation of pleasure, it also regulates our mood, emotional response, motor reactions and helps in regulating our movements. It is a major element in our ability to think, make decisions and plan. This neurotransmitter plays a crucial role in our mental and physical well being. Popularly known as the “feel-good” or “happy” hormone, DA regulates our motivation, pleasure & reward-driven behavior. When it is released, this chemical messenger makes us feel happy which motivates us to repeat the actions or behaviors that caused feelings of happiness or pleasure. However, the right balance of this neurotransmitter is very important as too much can lead to addictions and too little can cause various health issues, such as Parkinson’s disease. According to a 2016 research 2 by the Medical University of Vienna, DA is “responsible for our experiencing happiness.” However, it adds that “serious health problems can arise if too little or too much dopamine is being produced. If too few dopamine molecules are released, Parkinson’s disease can develop, while an excess can lead to mania, hallucinations and schizophrenia.”
How Does It Work?
As it is a neurotransmitter, this chemical is released by nerve cells for sending signals to other neurons. Our brain has different and distinctive pathways for DA which influences our reward-motivated behavior. The level of this neurotransmitter is increased by the anticipation of different forms of rewards 3. However, various addictive medicines and drugs can also increase it’s release or even block the reabsorption into nerve cells after release. DA pathways in the brain are also associated with regulating the release of different hormones and motor control.
A 2018 study 4 explains “Dopamine is a critical modulator of both learning and motivation.” Although dopamine is believed to be mainly responsible for pleasure, it actually regulates motivational salience 5, according to research 6. Hence, it regulates the recognized motivational value of a stimuli which drives our behavior, either desirable or aversive, towards the outcome. When a specific outcome or activity is mentally associated with pleasure by a person, then dopamine levels may rise simply by anticipating it. This could be related to food, shopping, sex or any activity that one may find pleasure in. However, it must be realized that DA works along with other hormones and neurotransmitters, like adrenaline and serotonin.
A 2010 research 7 states that “Dopamine regulates various functions in the CNS (central nervous system) and peripheral organs and is synthesized in the CNS and renal proximal tubule cells.” DA is highly important for our survival as it motivates and reinforces behaviors which assure our survival such as reproduction or eating high calorie foods. Apart from humans, dopamine is also present in most animals and plants.
How Dopamine Makes Us Feel?
DA regulates our desires and wants and makes us search for things and activities that can make us happy. It affects our goal-directed behavior and our arousal levels. It influences our drive to seek new information, gain knowledge and influences our curiosity regarding different ideas. This neurotransmitter creates a cycle of reward-seeking behavior so that we will repeat those behaviors which makes us happy and experience pleasure.
When we have high levels of DA, whether due to our mood, personality or even external stimuli, we tend to become sensation seekers. This affects our mindset and makes us think of potential stressors as obstacles which we need to overcome, instead of seeing them as threats. Such a mindset can enable us to cope with daily stress and live a more positive and successful life by boosting our resilience. However, low levels of dopamine can negatively affect our mental and physical health and lead to various illnesses.
Production Of Dopamine
DA is created in the brain in a dual process – creating the chemical dopa from the amino acid tyrosine and then changing it to the neurotransmitter dopamine. According to the International Encyclopedia of the Social & Behavioral Sciences, 2001 “Dopamine (DA) is found in three principle pathways: the mesolimbic/mesocortical pathways involved in motivation, reward, and cortical processing.” This organic chemical belongs to the phenethylamine and catecholamine families. Catecholamines 8 help to regulate our fight or flight response and involve the neurotransmitters Epinephrine (adrenaline) and norepinephrine (noradrenaline). Such neurotransmitters are formed and released from the brain and adrenal glands. DA, in particular, is released from the substantia nigra which is a part of brain tissue. A 2015 study 9 explains “Dopamine is a neurotransmitter that is produced in the substantia nigra, ventral tegmental area, and hypothalamus of the brain.” These neurotransmitters act as hormones in our body once released.
DA “plays a vital role in reward and movement regulation in the brain. In the reward pathway, the production of DA takes place in the ventral tegmental area (VTA), in nerve cell bodies. From there, it is released into the nucleus accumbens and prefrontal cortex,” add the researchers from the 2015 study. It is metabolized from phenylalanine and tyrosine. Nerve cells that are associated with this neurotransmitter are primarily located in the midbrain and help in managing motor function and sensory input.
Release Of Dopamine
DA is a process that involves a pattern of motivation, reward & reinforcement. Hence, this neurotransmitter is typically released when we experience pleasure. The release of this chemical messenger aims to reinforce the pleasurable actions and behavior which is associated with a reward. This helps to motivate the person to repeat the same behavior to experience that pleasing emotion or feeling. The release of dopamine triggered by certain behavior or activities mainly serves as a coping or survival mechanism. By feeling good about the outcome of a specific behavior, we will be motivated to repeat that behavior which will reinforce it further.
Some of the most common behaviors, activities and substances that can trigger the release of DA in someone include the following:
- Good, uninterrupted sleep
- Leisurely activities like music, movies or books
- Being out in the sun or in nature
- Medications & recreational drugs
Dopamine has a crucial role to play in our behavioral and physical well being. Although it is crucial for health and survival and certain behaviors such as getting enough sleep, meditating and exercising can be beneficial in the long run, the release of the neurotransmitter can also prove to be harmful as it may make someone addicted to junk food, alcohol and other unhealthy substances.
What Role Dopamine Plays
According to a 2016 study 10, “DA plays multiple functions in the brain.” The release and levels of DA affects several important brain functions such as concentration, memory, motor control, learning, motivation, mood, sleep, reward prediction and cognition, according to research 11. Aside from making us feel good or happy, this neurotransmitter helps to regulate various physical and behavioral functions in the body, such as:
1. Physical functions
- Heart rate & heart function
- Blood flow & blood vessel function
- Kidney function
- Pancreatic function & insulin regulation
- Regulates production of prolactin
- Regulation of vomiting & nausea
- Pain processing
- Motor control and movement
2. Behavioral functions
- Behaviour associated with pleasure & reward seeking
- Executive functioning
- Mood regulation
- Attention and focus
- Stress response and management
- Emotion regulation
- Goal-oriented behavior
- Regulates inhibition
- Social functioning (social anxiety or social phobia)
Balanced levels of DA is vital as this neurotransmitter helps in regulating our emotional responses and controlling our movements. Low DA levels or dopamine deficiency can not only affect our mental and physical well being, but it is also associated with various ailments, such as:
- Parkinson’s disease
- Huntington’s disease
- Attention deficit hyperactivity (ADHD)
However, DA deficiency 12 is usually not considered as a separate medical diagnosis. Low DA levels 13 can be caused by a fall in the amounts of DA production in our body or may be due to certain issues with receptors in the brain. Low levels of this chemical messenger can also lead to Dopamine deficiency syndrome, also known as Dopamine transporter deficiency syndrome (DTDS) 14 and infantile parkinsonism-dystonia. It is a rare, hereditary movement disorder which leads to increasingly aggravating parkinsonism and dystonia.
The disorder adversely affects the ability of a child to control their movements, muscle and body. Usually, symptoms tend to surface during infancy, however, in some cases symptoms may only arise later in childhood. Unfortunately, the condition is often misdiagnosed and so experts think that it may not be as rare as previously believed. Some of the most common symptoms of DTDS include the following, irrespective of the age it develops in:
- Muscle cramps and spasms
- Rigidity or stiffness in the muscles
- Bradykinesia or slow movement of muscles
- Aches and pains
- Loss of balance
- Difficulty standing upright and walking
- Difficulty in eating & swallowing
- Uncontrollable eye movements
- Gastroesophageal reflux disease (GERD)
- Thoughts of self-harm or suicide
The condition becomes progressively worse and there is no specific cure yet. However, treatment focuses on relieving and overcoming the symptoms. Moreover, dopamine deficiency treatment also relies on the presence of any underlying causes or conditions.
Read more to know about : Dopamine Deficiency
Dopamine Deficiency And Health Conditions
Most mental health conditions are likely influenced by a range of different factors as it is difficult to identify a single cause. However, studies show that unbalanced levels of DA may play a significant role in the onset of a number of psychiatric and physical health issues. DA deficiency can occur due to some issues with the brain receptors or lower amounts of production of this chemical messenger by the body. Research 15 reveals that “The brain dopamine system is involved in various neurological and psychiatric disturbances such as Parkinson’s Disease 16, schizophrenia, and amphetamine and cocaine addiction.” Researchers 17 have also found a link between low DA function in attention-deficit hyperactivity (ADHD) and Huntington’s disease 18.
Some conditions that may be influenced by this neurotransmitter include –
1. Parkinson’s disease
Parkinson’s disease 19 is a progressive neurodegenerative disorder which impairs our ability to control movement. DA regulates neurons in the brain which helps in movement control and communication. As a form of neuron constantly degenerates in Parkinson’s, it’s ability to send signals is impaired which adversely affects the body’s ability to produce DA. This also leads to various issues like poor coordination, poor balance, stiffness, slow movement and tremors. Research 20 reveals that “Reductions in DA content and uptake indices have been documented in Parkinson’s disease by a variety of techniques.”
2. Attention-deficit-hyperactivity disorder (ADHD)
Although the exact cause for the onset of ADHD is not known, some experts believe that a shortage of DA may be a significant factor. However, this may be caused by genetic problems 21. A 2003 study 22 reveals “The implication of SLC6A3 and DRD4 genes in ADHD appears to be one of the most replicated in psychiatric genetics and strongly suggests the involvement of the brain dopamine systems in the pathogenesis of ADHD.” Another 2012 study 23 states that dysfunction of the dopaminergic system is involved in ADHD.
It is believed that losing weight is a complicated process for obese individuals due to a dysfunction in their natural reward systems 24. They need to consume more amounts of food before they can feel satiated. According to a 2002 research 25, “The involvement of the DA system in reward and reinforcement has led to the hypothesis that low brain DA activity in obese subjects predisposes them to excessive use of food.” It has been observed that in people with obesity, there may be a shortage of production of DA and serotonin in the body. A 2001 study 26 explains “Dopamine modulates motivation and reward circuits and hence dopamine deficiency in obese individuals may perpetuate pathological eating as a means to compensate for decreased activation of these circuits.” Evidence 27 also suggests that impairments in DA signaling may also be associated with physical inactivity in obese people.
Schizophrenia 28 is a disabling, severe and chronic brain disorder that is mostly caused by genetic and environmental factors. However, unbalanced DA levels, especially a hyperactive dopamine system, may lead to hallucinations and delusions which are the primary symptoms of schizophrenia. Research 29 based on contemporary pathophysiological models believes that the psychotic symptoms may arise due to “a dysregulation of dopaminergic activity in the brain.” One 2014 study 30 found that DA is associated with the pathology of schizophrenia. The researchers state that “dopamine abnormalities in the mesolimbic and prefrontal brain regions exist in schizophrenia.”
Dopamine deficiency can lead to serious mental health conditions, like major depressive disorder and anhedonia. Studies 31 show that DA system dysregulation is closely associated with the onset of major depressive disorder. Anhedonia, which is a core aspect of depression is also significantly influenced by the DA system. A 1993 study 32 states that “dopamine likely contributes significantly to the pathophysiology of depression.” Further research 33 reveals that dopamine reuptake inhibitors, DA agonists and DA precursors tend to “show therapeutic efficacy in depression.”
Dopamine is also associated with addiction as individuals with substance use disorders may become increasingly dependent on the substance partially due to DA activation and release. According to a 2017 research 34, imaging “studies have shown that the reinforcing effects of drugs of abuse in human beings are contingent not just on DA increases per se in the striatum (including the nucleus accumbens) but on the rate of DA increases.” Certain addictive drugs 34 can lead to rapid increase of this chemical messenger in the brain which significantly stimulates the reward system. But continuous stimulation and satisfaction of the natural reward system raises the pleasure threshold. As a result, the drug abuser needs to take increasing amounts to experience the same effect.
Moreover, drugs reduce the body’s natural ability to naturally produce DA. A recent 2020 study 35 states “As a result of habitual intake of addictive drugs, dopamine receptors expressed in the brain are decreased, thereby reducing interest in activities not already stamped in by habitual rewards.”
7. Alzheimer’s Disease (AD)
Apart from these, dopaminergic dysfunction may also play a pathogenic role in cognitive decline symptoms of Alzheimer’s Disease (AD), a neurodegenerative disorder, according to a study 36. The researchers explain that “Different degrees of DA dysfunction can occur during any phases of AD. The most important symptoms related to DA dysfunction are the presence of apathy and EPS (extrapyramidal signs).”
Ways To Increase Dopamine
DA is a vital neurotransmitter that plays several important functions in the brain. Although DA levels are usually well maintained in the nervous system, you can take the following self-care steps to increase dopamine in the brain naturally:
- Consume foods that are rich in protein and the amino acid tyrosine 37 such as fish, eggs, meat, dairy, legumes, soy, nuts and seed etc.
- Take vitamin 38 and mineral supplements that contain magnesium, iron, vitamin B6, vitamin D, curcumin, folate etc.
- Avoid foods that contain high fats and sugar such as processed foods.
- Practice good sleep hygiene as quality, undisturbed sleep 39 helps to produce dopamine
- Regular exercise 40 and physical activity can also help to improve DA levels
- Practice relaxation techniques like meditation 41, breathing exercises and visualization to avoid stress.
- Consume probiotics 42 whether through foods like fermented foods or yogurt or even supplement to promote DA production.
- Listen to instrumental music 43 as it can support dopamine release in the brain.
Apart from these, maintaining a healthy lifestyle, following a balanced diet and spending some time in sunlight can also boost DA levels.
Read more to know about : How To Increase Dopamine
Dopamine As Treatment
This neurotransmitter is a direct-acting catecholamine which can be effectively used in laboratory and clinical situations and is medically considered as a lifesaver. Dopamine hydrochloride (Intropin) is widely prescribed by doctors for the treatment of poor cardiac performance, low blood pressure, poor flow of blood to vital organs and even in the treatment of septic shock 44. According to a study 45, Intropin “has been used in the postoperative management of open-heart surgical patients, both children and adults,” with an exceptionally low incidence of negative responses.
However, there may be certain side effects associated with DA for treatment, such as –
- Chest pain
- Increased heart rate
- Difficulty breathing
- Nausea & vomiting
Hence, it is crucial to consult a doctor before taking any DA medications for the treatment of different ailments and illnesses.
Dopamine: The Pleasure Hormone
Dopamine is involved in a number of essential neurological & cognitive processes and affects our mood, pleasure and motivation. It significantly affects the motivation-reward-reinforcement cycle which influences our goal-directed behavior. Although a lot of research has been conducted on DA, there is still a lot to understand about how this neurotransmitter interacts with hormones and other neurotransmitters.
If you believe that you are experiencing DA deficiency or any associated ailments, then make sure to consult a doctor immediately.
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