Dopamine is a neurotransmitter produced naturally by humans, as well as most animals and many species of plants. Besides being a neurotransmitter itself, it is also a precursor to the neurotransmitters norepinephrine and epinephrine.
In the human body, dopamine is created via a limited number of cell types. These are primarily nerve cells (neurons) and cells in the adrenal medulla, found in the central part of the adrenal gland enveloped by the adrenal cortex.
As a person ages, the biosynthesis of dopamine decreases as does dopamine receptor density. This might contribute to decreased cognitive ability in the elderly, as well as affecting other neurological problems they face.
Low levels of the neurotransmitter dopamine can be the result of things like genetics, hypothyroidism, stress, bad diet, the flu, lack of sleep, withdrawal from drugs, exposure to hazardous chemicals, nutrient deficiency, other reasons.
Symptoms associated with low dopamine levels include:
--- Reduced Energy.
--- Memory Problems.
--- Slow Reaction Time.
--- Reduced Motivation.
--- Restless Leg Syndrome.
--- Difficulty Concentrating.
--- Decreased Interest In Sex.
--- Reduced Social Interaction.
--- Reduced Tolerance To Stress.
--- Insomnia Or Too Much Sleep.
--- Being Very Slow In The Morning.
--- A Need To Consume Sugar And Carbohydrates.
--- Decreased Biological Activity (slower bodily processes).
Individuals diagnosed with Parkinson's Disease have lower levels of dopamine in parts of their brains, when compared to people who do not have the disease. Parkinson's Disease impairs movement and may include tremors.
Various medications and dietary supplements are available to enable your body to perform tasks like releasing more dopamine (dopamine releasing agents) or inhibiting the reuptake of dopamine (dopamine reuptake inhibitors).
In either case, the net result of ingesting any of these is an increase in dopamine levels for your body to work with. Depending on your particular needs, one might work better for you than others.
There are also dopamine precursors like Phenylalanine, Tyrosine, L-dopa, that can aid your body in producing (biosynthesizing) dopamine. Dopamine precursors are chemicals your body converts to dopamine.
To produce dopamine in the human body:
Phenylalanine is converted to Tyrosine.
Tyrosine is converted to L-dopa.
L-dopa is converted to Dopamine.
See the section on this page about decreasing dopamine levels for more information about drugs that increase and decrease dopamine. A list of some supplements and precursors that can increase dopamine levels can be found here.
High dopamine levels may cause:
Feeling Stressed Out.
Thrill Seeking Behavior.
When the level of dopamine in the brain gets too high, most people begin to show signs of losing touch with reality. Individuals that suffer from paranoia and obsessive compulsive disorder (OCD) usually have elevated levels of dopamine in their brain.
Excessive levels of dopamine may be present in the manic stage of bipolar disorder. Some types of schizophrenia are associated with high dopamine levels. Hallucinations and various symptoms of psychosis can be triggered by too much dopamine.
People with naturally high levels of dopamine tend to like exciting or even dangerous activities. This might not be a problem unless it endangers lives. However, when dopamine levels get to the point of excess they can cause a loss of touch with reality.
A list of dopaminergic drugs can be found at wikipedia. These chemicals all affect dopamine or dopamine receptors. Most of these substances increase dopamine levels (or trigger dopamine receptors to fire) but some of them inhibit the effect of dopamine.
Agonists - effects are similar to increasing dopamine levels.
Antagonists - will decrease the effect of dopamine.
Reuptake Inhibitors - increase dopamine levels.
Releasing Agents - increase dopamine levels.
Enzyme Inhibitors - increase dopamine levels.
Precursors - can increase dopamine levels.
If you are experiencing the effects of excess dopamine levels, dopamine antagonists will bind to dopamine receptors and reduce the signal they send or stop them from sending any signal. This will lessen the effect of excess dopamine and could bring relief.
Most medications classified as antipsychotic will reduce the effect of dopamine. But they can have side effects that are as bad or worse than excessive dopamine levels themselves. The side effects can be so bad that people stop taking them all together.
Many medications increase dopamine levels as part of their method of action. While this is usually a good thing with a desired outcome, it can turn bad if they raise dopamine levels and get to the point where dopamine is excessively high.
If you are taking a drug that increases dopamine and you show signs of suffering from excessive levels, lowering the dose or finding an alternate medication that does not increase dopamine as much might be the best course of action.
Almost all recreational drugs that have addictive potential increase dopamine (amphetamines, cocaine, opioids...). In small doses these drugs can be beneficial. But large doses, and/or extended periods of use, can cause a psychotic reaction.
For example, a person smoking crack for several days straight may get to the point where they become psychotic. Psychosis means believing things that are not true. A person suffering from psychos is said to be psychotic.
1 --- Low dopamine levels lasting extended periods of time often result in chronic pain, among other things. If you are experiencing chronic pain of unknown origin, increasing dopamine levels may help.
2 --- People with ADHD will usually have a positive response to medications that increase dopamine levels. The most effective medications for the treatment of ADHD (like adderall, ritalin, opioids) increase dopamine levels.
3 --- If you are taking any dopamine precursor like Phenylalanine, Tyrosine, or L-dopa to increase dopamine levels, but they aren't effective, taking a multivitamin a few hours prior may help. Vitamin B6 may interfere with the absorption of L-dopa so it is best not to take vitamin B6 at the same time as dopamine precursors.
Wikipedia dopamine page.