The neurotransmitter dopamine is very important but is much less well known than serotonin. Remember that much of what we know about the function of the different neurotransmitters has been discovered by studying the effects of pharmaceuticals with known mechanisms of action that involve neurotransmitter levels. It’s also important to note that changes in the levels or activity of one neurotransmitter will usually affect the level and activity of other neurotransmitters. For example the chronic use of SSRI drugs which increase serotonin often show the unwanted side effects called “poop out” syndrome. This is characterized by decreased libido, motivation, creativity, drive and initiative but without depressed mood. The theory is that such changes occur because the extra serotonin blocks dopamine in other parts of the brain. Even if the SSRI is increased, these symptoms probably will not improve. The SSRI must be decreased or another agent added, or proper supplementation utilized to increase dopamine signaling in the prefrontal cortex.
As suggested above, dopamine is important for a variety of mental functions not necessarily related to anxiety or depression. Neurons which depend on dopamine for neurotransmission (dopaminergic neurons) are found in the limbic system, the mid-cortex, the nigrostriatal region, and the tuberoinfundibular bundles (related to prolactin levels). The typical antipsychotic drugs that have long been in use by psychiatrists work because they tune down the excess dopamine effects in the limbic system that produce positive psychotic symptoms (ie phenomena that should not normally occur) such as hallucinations and delusions. However, psychotic patients also suffer from thinking and motivation disturbances (the so called negative psychotic symptoms…ie things that should be present but are not) which is due to inadequate dopamine stimulation of the midcortex. Therefore by further blocking dopamine’s effect, the typical antipsychotic drugs help the “crazy” symptoms but also make the average patient more like a “zombie” who lacks drive, energy, vitality, and libido. Some of these “unwanted” effects have been specifically exploited in institutions using these drugs as “chemical restraints” in chronic mental patients, sex offenders, and the criminally insane. The other unwanted effect of these drugs is a symptom complex that looks just like Parkinson’s disease (extrapyramidal symptoms). This occurs because they artificially reduce dopamine effect in the nigrostriatal area, specifically the substantia nigra, which is the same part of the brain where natural depletion of dopamine eventually results in Parkinson’s disease. If you think of what a Parkinson’s disease patient looks like, stiff, immobile, lack of expression on the face, tremulous, slow reaction time you can see the end point of dopamine depletion.
With that lesson in pharmacology as a backdrop then, what do we need to know about dopamine? First, dopamine effect can be diminished by interference from the serotonin effects of the SSRI class of drugs. One goes up the other goes down. In human physiology there are many interrelationships and balances between chemical messengers. Using SSRI drugs or nutrients that increase serotonin may lead to depletion of dopamine with its associated symptoms. Second, the aging process takes an inevitable toll on dopaminergic neurons via oxidative stress. The most dramatic manifestation of that process is Parkinson’s disease, previously known as the “shaking palsy”. Theoretically if man lived long enough, the incidence of Parkinson’s disease would approach 100%. Dopamine content of the brain is stable until age 45, and then decreases linearly about 13% every decade. When the loss of dopamine reaches 30% Parkinsonian symptoms may begin. I feel the rate of decay in dopamine content is subject to modification by nutritional and other interventions.
Third, we should be aware of the earlier manifestations of the loss of dopaminergic neurons. Loss of drive and vitality is the clearest signal, along with poor motivation, loss of joy generally, low sex drive, diminished sexual performance and pleasure from sexual activity, and lessened intensity of orgasms are common. Another, even earlier, sign of trouble is the inability to remember one’s dreams, or a complete discontinuation of dream activity. The beta waves on a brain EEG are the ones associated with alertness and they originate in the frontal lobes of the brain from neurons that produce and depend on dopamine, which controls the electrical voltage of your brain. Overall dopamine works as a natural amphetamine that controls your energy, excitement and motivation. It is also related to blood pressure, metabolism, digestion, voluntary movement, intelligence, abstract thought, setting goals, and long-term planning.
Those individuals with a predominant dopamine nature who are balanced know what they want, are assertive, strong-willed, fast on their feet and self-confident. Dopamine personalities tend to like facts and figures are highly rational and are achievement oriented. Dopamine types gravitate toward occupations such as law, science, allopathic medicine, engineering, architecture and the military.
Producing too much dopamine can make one too intense, compulsive and driven. Overproduction of dopamine can also lead to violent behavior. Dopamine deficiencies can lead to some of the following symptoms:
Anemia
Blood sugar instability
Bone density loss
High blood pressure
Low sex drive and/or difficulty achieving orgasm
Joint pain
Thyroid disorders
Aggression (paradoxically)
Anger
Depression
Inability to handle stress
Guilt or feelings of worthlessness
Excessive sleep
Mood swings
Slow thought processing speed
Forgetfulness
Attention deficit disorder
Hyperactivity
Failure to finish tasks
Severe dopamine deficiencies are often treated with medications or hormones. Mild to moderate dopamine deficiencies can be balanced with diet, supplements and lifestyle modifications. Physical signs of dopamine deficiency will be fatigue, sleeping long hours and still not feeling rested, your mind wandering, difficulty making decisions, craving caffeine, sexual dysfunction. Unconsciously you will try to compensate by avoiding stressful situations, drinking coffee to give you energy and drinking alcohol to bring you down. It is important once you realize this to correct your underlying dopamine deficiency with proper nutrition, supplementation and lifestyle modifications.
Other strategies that the person interested in anti-aging medicine may employ include lifelong antioxidant supplementation which may slow the rapid deterioration in neuron health and dopamine levels later in life. Furthermore, each of the primary neurotransmitters has a nutrient precursor, and dopamine is derived from the amino acids phenylalanine and tyrosine. Co-factors such as folic acid, vitamin B6, iron, copper and vitamin C are important for phenylanaline to be absorbed and utilized, but phenylalanine is not a useful supplement to employ in the attempt to raise dopamine levels. There are too many other pathways whereby the body utilizes that amino acid, therefore most of it is NOT used in the production of dopamine. Instead, extra vitamin B6 (which increases tyrosine peroxidase, which increases dopamine) as a supplement as soon as loss of dream recall begins to occur makes sense. The amino acid tyrosine is a more direct precursor to dopamine, and can also be usefully prescribed in those on SSRI or antipsychotic drugs, or amino acid therapy targeting serotonin levels in order to prevent/correct dopamine depletion. Macuna pruriens is a supplement that contains a naturally occurring form of dopamine. A pharmaceutical of great interest in the battle against neuron death and dropping dopamine levels is deprenyl. This is one of the drugs which inhibits the enzyme monoamine oxidase and therefore increases dopamine effect at the neuron synaptic junctions. Apart from being one of the most indicated drugs for Parkinson’s disease (a dopamine deficiency disease), in lower doses and in the right form it is an excellent way to restore full function of dopamine dependent parts of the brain. It also prevents neuron cell death by enhancing certain antioxidant levels. This medication requires a prescription, and should be used under an anti-aging physicians guidance, but all the literature suggests that deprenyl may be a premiere preventative and treatment for age related mental, emotional, and physical decline.
Dopamine is a crucially important brain neurotransmitter. Deficiencies or imbalances can be diagnosed by clinical symptoms and urine neurotransmitter evaluation. Natural remedy and safe low dose pharmaceutical treatments are available and effective in restoring balance, reducing symptoms, slowing aging, and enhancing quality of life.
