Dopamine – Emotions
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Oct. 24, 1996
Dopamine linked to a personality trait and happiness BySusan S. Lang
Richard Depue
Adriana Rovers/University Photography
In this 1995 photo, Richard Depue measures changes in the diameter of the pupil of the eye during different light conditions to determine individual differences in the activity of the brain chemical norepinephrine.
Researchers have long suspected that the chemistry of the brain largely influences personality and emotions. Now, a Cornell clinical psychologist has shown for the first time how the neurotransmitter dopamine affects one type of happiness, a personality trait and short-term, working memory.
“One personality trait in humans is how sensitive and responsive we are to incentives and rewards,” said Richard Depue, professor of human development and family studies and director of the Laboratory of Neurobiology of Personality and Emotion at Cornell. Depue is an expert in the neurobiology of personality, emotion and temperament with particular expertise in the neurotransmitters dopamine, serotonin and norepinephrine. “Some of us are motivated by signals of incentive-reward and pursue goals, and others are not.”
A major reason for the difference, he argues, is related to different levels of or responsiveness to dopamine, one of the chemical substances that transmits nerve impulses through the brain.
From a series of experiments with humans and based on what was already known from animal studies, Depue has concluded that dopamine is strongly related to the trait some researchers call extraversion, but Depue and his colleagues prefer to refer to it as “positive emotionality.”
“This is the first time it has been shown in humans that a central nervous system neurotransmitter is associated strongly with an emotional trait in humans,” Depue said.
The higher the level of dopamine, or the more responsive the brain is to dopamine, the more likely a person is to be sensitive to incentives and rewards. “When our dopamine system is activated, we are more positive, excited and eager to go after goals or rewards, such as food, sex, money, education or professional achievements,” Depue said.
To examine this relationship, Depue first measured this trait in volunteers using personality tests. He then used Ritalin, an amphetamine widely prescribed for attention deficit disorder, to activate the dopamine system. How much the dopamine system is activated can be assessed by levels of a hormone (prolactin) in the blood and by changes in the rate of spontaneous eye blinks, which previous studies have shown to be significant.
Depue found that how reactive someone is to dopamine highly correlates with high scores on positive emotionality. People who responded easily to the drug and showed an increase in spontaneous eye blinks had a more active dopamine system in general and, Depue suspects, feel happier than others in response to incentives.
“We have strong evidence that the feelings of being elated and excited because you are moving toward achieving an important goal are biochemically based, though they can be modified by experience,” Depue said.
By better understanding the role of dopamine in humans and how temperament types and personality traits can be driven biochemically, we can glean insight into personality and psychological disorders, Depue suggests. “There is now overwhelming evidence that 50 to 70 percent of individual variation in personality trait scores, for example, is related to genetic influence,” he said.
Depue now is measuring the emotional responses of volunteers to emotional film clips before and after their dopamine systems have been stimulated or with the use of a placebo.
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Low Dopamine Levels: Symptoms & Adverse Reactions
Dopamine is a neurotransmitter that is involved in many necessary brain functions. It is released when we get rewarded and is linked to feelings of pleasure. The pleasure associated with the release of dopamine is what makes certain behaviors addictive. Any behavior that induces a sense of pleasure such as: gambling and winning, doing certain drugs, drinking alcohol, having sex, or eating candy – all stimulate the dopaminergic system.
Unfortunately excessive release of dopamine via certain behaviors can lead to a dopamine sensitivity and/or even a reduction in dopamine levels. Someone who uses amphetamines over a long-term gets an initial “high” or pleasure from the short-term increase in dopamine. Over the long-term, the amount of dopamine becomes depleted, leading the user to require higher doses to experience the same pleasurable effect.
Low dopamine is an inevitable side effect of certain addictions, but is also a consequence of certain conditions like schizophrenia and neurodegenerative diseases. If you have low dopamine or excessively low dopamine, chances are that it’s impairing your mental performance. Although too much dopamine can create problems, too little dopamine may be even more problematic.
Low Dopamine Symptoms: List of Possibilities
Since dopamine is involved in a variety of brain functions, low extracellular levels of this neurotransmitter can result in a variety of unwanted symptoms. Keep in mind that the severity and number of symptoms you experience as a result of low dopamine is subject to individual variation.
Attention deficits: Many individuals with attentional deficits are speculated to have abnormally low levels of dopamine. If you have below average levels of dopamine, it’s going to make it tougher to pay attention and focus. We know that administration of amphetamines (drugs which elevate dopamine) is able to improve attentional capacities of individuals who struggle with attention. Low dopamine may not be the sole reason for attention deficits, but those with lower than average dopamine will likely struggle to focus their attention.
Anxiety: Those with anxiety disorders have probably heard that high dopamine can exacerbate nervousness, tension, and anxiety. Certainly higher than average dopamine can be problematic, but abnormally low dopamine causes anxiety in a subset of individuals. These individuals often find that taking a drug like Adderall for anxiety actually improves their symptoms.
Blunted affect: A decrease in the level of dopamine often results in a person to appear “blunted” or as if they have emotionally flat-lined. They won’t show much capacity for expressing feelings of joy, excitement, happiness, but they also won’t really express sadness or panic. Low dopamine causes a person to appear emotionally “grey” or as if they’ve become a robot.
Cognitive impairment: It’s tough to perform well cognitively when you don’t have enough dopamine. Insufficient dopamine can result in suboptimal job performance, inability to complete cognitively-demanding tasks, and poor memory. As a means to optimize dopamine levels, many top-performers supplement agents or drugs that deliberately elevate their brain’s baseline dopamine level.
Confusion: It’s relatively easy to become confused when your brain isn’t producing enough dopamine. Learning new things won’t make as much sense as they should, you may experience excessive brain fog, and have a difficult time functioning in society. Increasing dopamine tends to decrease confusion and promotes psychomotor vigilance.
Depersonalization: Dopamine promotes emotional expression and helps us process how we feel. With low levels of dopamine, it may feel as if all of the color and zest gets sucked out of life. A person with dopaminergic-based depersonalization may feel as if no activity brings them pleasure. They feel as if their “core” personality has changed and as if they are observing themselves from a third-person perspective. It is common for addicts with low dopamine to become depersonalized.
Depression: Low dopamine can be a major contributor to depressive symptoms. Anyone with abnormally low dopamine is likely to experience a depression that differs from a serotonergic depression, despite the fact that both share common overt observational symptoms. Those that end up taking a drug like Adderall for depression over a long-term with success may have needed a dopamine boost rather than serotonin.
Disorganized thinking: Those who have severely disorganized thinking tend to have low levels of dopamine. Sufficient dopamine helps us organize and logically sort through our thoughts. Those that develop conditions like disorganized schizophrenia may have abnormally low dopamine in certain parts of the brain.
Fatigue: Without enough dopamine for fuel, you may feel excessively tired or lethargic. When a person that’s been using amphetamines daily for an extended term stops using them, they typically feel more tired than usual. This is a fatigue that’s directly influenced by abnormally low levels of dopamine. Over time without a relapse, the dopamine stores will increase and energy levels will normalize.
Lack of motivation: Low dopamine can also lead to avolition or severe motivational deficits. Slightly reduced dopamine production may make you feel more tired than usual and feel lazy. Severe deficits can result in motivational impairment to the point that it’s difficult to justify doing work or engaging in proper self-care.
Learning problems: If you’re a person with low dopamine and are attempting to learn new information, your ability to learn is diminished. It may seem as if you’re reading or hearing information, but it’s going in one ear and out the other. Almost like you cannot absorb the new informational stimuli that you’ve presented your brain.
Poor concentration: You may have foggy thinking, be susceptible to daydreams, and have a tough time focusing when necessary. Low dopamine can create a state of mental fogginess, making it tougher than usual to concentrate. This is why those with concentration problems often find that ADHD medications (or psychostimulants) improve their ability to focus.
Inattentiveness: Those with the inattentive subtype of ADHD may get the most benefit from increasing their dopamine. While low dopamine certainly isn’t the only factor that causes inattentiveness, it likely plays a role. Inattentiveness can sometimes be offset by increasing extracellular levels of dopamine.
Low libido: A person with low dopamine tends to have a reduced interest in sex. They may have less desire to seek out a sexual partner and may have a non-existent sex drive. In some cases anorgasmia or inability to orgasm may result due to the fact that they lack dopamine to sustain interest. Low libido tends to quickly turn around when dopamine levels increase.
Memory impairment: Those with neurodegenerative diseases often suffer memory impairment as a result of dysfunction within the brain’s dopamine system. The dysfunction results in abnormally low amounts of dopamine and memory functions become impaired. While low dopamine certainly isn’t the only cause of memory problems, increasing dopamine (via pharmaceuticals) tends to help improve recall.
Monotone speech: A person’s speech may become extremely monotone, which is indicative of the fact that they are lacking pleasure. Life isn’t really as “bright” as it should be when dopamine levels are low. Voices of those with low dopamine may sound robotic and lack any emotional enthusiasm in a positive or negative direction. This is associated with blunted affect which was mentioned earlier.
Sleepiness: If your dopamine levels are low, you may feel more sleepy than usual. It isn’t uncommon to engage in excessive sleep as a way for your brain to increase dopamine production. Those withdrawing from stimulatory drugs like amphetamines typically notice that they are more sleepy than usual upon discontinuation. This is due to the fact that their dopamine levels are below baseline.
Slow thinking: While thinking slow can sometimes be a result of preexisting genetically homeostatic neural pathways, it can also be a result of a dopamine deficiency. Those that consider themselves “slow thinkers” may find that their thinking is further slowed with reduced dopamine. Increasing dopamine tends to increase arousal, beta brain waves, and thought speed.
Social withdrawal: Since low dopamine saps the pleasure from life, it is common for those with low levels to withdraw from social situations. A person may no longer get pleasure from talking to friends, partaking in social activities, etc. The dopaminergic “feel good” reward from engaging with others in social situations is no longer present. This can provoke social isolation, which over time, can also result in poorer functioning of dopamine.
Weight changes: Generally a person with low dopamine may not derive as much interest in eating food as someone with greater production of dopamine. However, most people with low dopamine find that their metabolism is slowed, they sleep more than usual, and have a difficult time sustaining physical activity. This usually results in weight gain whereas higher dopamine production tends to stimulate weight loss.
Low Dopamine Adverse Reactions
If you have excessively low dopamine, you may run into problems with coordination, balance, communication, and thinking. Understand that excessively low dopamine tends to occur with neurodegenerative diseases and severe mental illness.
Balance difficulties: Since dopamine is involved in motor functions and balance, someone with a deficiency may have difficulty maintaining proper balance. They may also find that their coordination is substantially impaired in direct relation to low dopamine production.
Inability to write: Writing is an activity that requires significant cognitive horsepower. One of the neurotransmitters that fuels a person’s ability to write with clarity and focus is that of dopamine. If you’re lacking dopamine, you may have writing difficulties or may not be able to write at all (assuming your coordination is also affected). Think of a case of writer’s block on steroids.
Postural changes: Low dopamine can result in postural changes. A person with low dopamine may sit with a rigid posture or may appear completely stiff and uncomfortable. This is likely due to the fact that certain regions of the brain (e.g. motor circuits) aren’t getting the dopamine necessary to operate properly.
Severe disorganization: While disorganization is often a common sign of schizophrenia, it can be a sign of a number of other dopaminergic disorders. Dopamine dysfunction accompanied by low levels can result in disorganized thinking, behavior, communication, etc. A person may lose their entire capacity to function logically.
Speech problems: A person with deficient dopamine may have disorganized speech and/or may not be able to properly speak. Some people with low dopamine may speak infrequently, babble, or make sounds rather than elocute words properly. This is a problem that
Tremors: Some tremors and restlessness may be fueled by insufficient dopamine production. While lack of dopamine is not always the sole cause of “shakes” or tremors, it can be a contributing factor. Medications that increase dopamine to standard levels can help offset this problem.
How to Increase Dopamine Levels
If you have low dopamine, there a variety of ways in which you can increase it. If the low dopamine is a result of a mental illness or a neurodegenerative disease, talk to your doctor about what can be done. If you don’t have any diagnosable condition but want to increase your dopamine, your best bet is making dietary changes and/or considering a supplement like L-Tyrosine.
Dietary interventions: Those that suspect their dopamine level is slightly below the norm should first make dietary changes. Start eating dopamine rich foods like eggs, fish, poultry, and red meat. Foods that are high in protein tend to increase levels of dopamine. Additionally foods containing “tyrosine” like cheese, beans, dairy nuts, and seeds may also help.
Drugs: There are a variety of pharmaceutical drugs (e.g. dopamine reuptake inhibitors) that are utilized to increase dopamine in patients that clearly need a boost. Generally those that need phamaceutical-grade dopamine increases have been diagnosed with conditions like Parkinson’s disease. Other conditions such as certain types of ADHD, depression, reward deficiencies, etc. may also benefit.
Supplements: If you’ve made dietary changes, but still aren’t finding them to be quite enough to elevate your dopamine, there are some supplements that you could consider taking. Both of the supplements recommended act as precursors to the production of dopamine. Your body converts them into dopamine upon ingestion.
L-Tyrosine
L- Phenylalanine
Conditions associated with Low Dopamine
There are many psychological disorders related to low dopamine production in the brain. While some of them are more related to dopamine dysfunction rather than low extracellular levels, research has also suggested that low dopamine may be more likely among individuals with these conditions.
Addiction: People that are addicts to certain behaviors or stimuli (e.g. drugs) find that they get a temporary boost in dopamine when engaging in the activity. Unfortunately this temporary boost cannot be sustained for a long-term. Sustained engagement in certain addictions may actually lower the endogenous supply of dopamine in the brain; this is seen in those addicted to amphetamines. Only stopping the addictive behavior for a long-term will result in dopamine levels to increase.
ADHD: There are numerous types of ADHD, some of which may be a result of low dopamine. While dopamine is not the only cause of ADHD, increasing levels may help a person cope with their condition. This is why many dopaminergic agents (e.g. L-Tyrosine) tend to be used as effective Adderall alternatives.
Anxiety disorders: It is important to realize that most types of anxiety disorders do not stem from low dopamine. People that find increasing their dopamine levels helps with anxiety are in the minority, but certainly exist. Those that find psychostimulants beneficial for easing their anxiety symptoms may have substandard levels of dopamine or dysfunction within the dopamine system.
Autism: There have been numerous dopamine defects found in individuals with autism. Researchers have found that the dopamine signaling is altered as a result of certain genetic expression. While there aren’t many good treatments for those with autism on the market, pharmaceutical firms are looking to target the observed dysfunction by targeting the dopamine transporter.
Bipolar disorder: While it is unknown as to what causes the depressive phase of bipolar disorder, some speculate that low dopamine may be symptom. Those with this condition should be working with a medical professional to determine what neurotransmitter increases and/or decreases yield the most benefit. In some cases taking a drug that raises dopamine can be helpful to cope with the depression, but caution must be taken to avoid the transition to mania.
Depression: Not all types of depression are caused by low dopamine, but some are. Certain subtypes of depression tend to benefit more from drugs that increase dopamine (e.g. Wellbutrin) than those that increase serotonin. I’ve written an article discussing the fact that dopamine can cause depression just as easily as serotonin.
Drug abuse: Those that abuse drugs may have deficiencies in multiple neurotransmitters (depending on the drug). If the drug flooded the brain with dopamine, in the process it may have used up dopamine stores and caused some dysfunction. This drug-induced dopamine dysfunction may take some time to correct itself and likely won’t correct itself unless the person abstains from drugs.
Neurodegenerative diseases: Those that are experiencing neurodegenerative diseases tend to have diminished production of dopamine, particularly in Parkinson’s. This leads to problems with walking, posture and movement, followed by cognitive impairment. It has been established that those with Parkinson’s aren’t able to produce dopaminergic neurons in the midbrain. This means that drugs like L-Dopa (synthetic dopamine) are commonly prescribed to help boost levels.
Reward deficiency syndrome: Those suffering from a theoretical condition known as “reward deficiency syndrome” (RDS) are thought to have insufficient dopamine production in certain parts of the brain. The low dopamine leads people with RDS to seek out addictive behaviors as an attempt to increase their lower-than-average baseline dopamine, which makes the person feel more “alive” rather than blunted. Unfortunately many of these behaviors (e.g. addictive drugs) provide a temporary increase in dopamine, but deplete levels over the long-term; which exacerbates the condition.
Schizophrenia: Certain types of schizophrenia are believed to be a result of low dopamine. While all cases tend to exhibit dopaminergic dysfunction, not all cases are associated with paranoia and delusions. In fact, the negative symptoms of schizophrenia are likely in part influenced by low dopamine. These negative symptoms tend to include things like: blunted emotion, monotone voice, lack of energy, avolition, and disorganization. Some of the cognitive symptoms of schizophrenia may also be a reflection of low dopamine.
Have you experienced low dopamine?
If you’re a person that’s dealt with low dopamine, feel free to share your experience in the comments section below. How did you know that low dopamine was contributing to your problem and can you really be sure that dopamine was to blame? Many people think they automatically have “low dopamine” because a medication like a psychostimulant helps them perform better.
Slight elevations in dopamine are going to help even a non-dopamine deficient person perform better. Therefore it is really difficult to know with 100% accuracy that low dopamine is a problem in any particular case. However, certain conditions like Parkinson’s disease tend to result from dopamine deficiencies. In this case, increasing dopamine is known to help.
To help others get a better understanding of your situation, talk about whether you’ve been formally diagnosed with a condition associated with low dopamine and how increasing your dopamine levels have helped.
He also points out that some research suggests that low levels of serotonin, which can result in irritability and volatile emotions, also may make people more responsive to dopamine. These people, therefore, may be more susceptible to drugs that activate the dopamine system, such as cocaine, alcohol, amphetamine and, to a lesser extent, opiates and nicotine. One theory is that different dopamine receptors in the brain may be related to different types of abuse and that people who have particularly low dopamine functioning may be more susceptible to depression and Parkinson’s disease.
In related research, Depue has shown that dopamine is strongly related to how well the prefrontal cortex holds information. “To hold in short-term memory a spatial map of the environment, for example, you must have the dopamine system activated; without it, you can’t do this type of cognitive functioning,” Depue concludes from his research in this area.
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