Everyone can feel depressed at times. Bad weather, bad news, or just the blahs can make you feel down and diminish your desire to engage in fun and productive activities or do just about anything at all. When these feelings persist and are accompanied by loss of appetite, self-isolation, suicidal thoughts, or other adverse thoughts and behaviors, it is very likely that a chemical imbalance of brain neurotransmitters is part of the problem.
Serotonin’s Effect on the Brain
Serotonin is a neurotransmitter, otherwise known as a chemical messenger, that acts in the brain to regulate mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function. Serotonin was linked to depression around 50 years ago when it was observed that drugs that decreased serotonin levels often caused depressive side effects.
Conversely, drugs like monoamine oxidase inhibitors that enhanced serotonin activity appeared to have anti-depressant effects. Monoamine refers to a type of chemical that includes serotonin as well as other neurotransmitters and compounds. An oxidase is an enzyme that breaks down the compound, so if you inhibit this enzyme, you increase the amount of the neurotransmitter.
Drugs that acted more specifically on serotonin and other neurotransmitters, such as “selective serotonin reuptake inhibitors,” were developed to diminish side effects and improve efficacy. “Uptake inhibitor” means that the drug prevents the removal of serotonin, thereby effectively increasing the amount of serotonin available to act in the brain.
Another proven effective way to increase serotonin levels in the brain is to raise the blood level of the amino acid tryptophan. Tryptophan is a precursor of serotonin, so an increase of tryptophan in the blood increases the amount of tryptophan in the brain, which in turn produces more serotonin. Many people have reported that tryptophan supplements can help alleviate depressive symptoms and improve mood.
It would all appear, then, to be very straightforward, that the key to combating depression is to maximize serotonin functioning in the brain, be it with serotonin drugs or serotonin supplements made up of amino acids for depression, such as tryptophan. Of course, it isn’t that easy. There are many neurotransmitters that act in concert in the brain to regulate mental states as complicated and nuanced as mood.
The Delicate Nature of Antidepressants
Other antidepressants that have proven to be effective at alleviating depression act on the neurotransmitters norepinephrine and dopamine. The relationship between serotonin and dopamine in the context of depression is complex. Many drugs targeting serotonin also indirectly affect dopamine receptors, and it may be that in some individuals low dopamine levels may be responsible for depressive symptoms.
Adderall, a drug prescribed for attention deficit disorder, increases levels of serotonin, dopamine, and norepinephrine in the brain, and has been used in some cases to treat depression. Since these neurotransmitters are messengers in the brain’s reward and motivation pathways, it follows that they are responsible for the regulation of emotions and feelings of pleasure. A new focus in antidepressant development is the enhancement of these neurotransmitters by way of inhibiting reuptake of all three. A concern with this pharmacology is the potential for misuse and addiction, a valid worry given the problems that have been observed with Adderall abuse.
A New Take on Depression
Recently, investigators have taken some novel approaches to thinking about depression. Depression is not only a condition of sadness. Anxiety, anger, frustration, and helplessness are other emotions and feelings that link with depression. Poor physical health and even chronic inflammation can also bring about depression.
Some experts have proposed that the proper balance of neurotransmitters in the brain is crucial for developing positive learning associations and coping strategies. They suggest that a deficit of serotonin is related to anxiety, obsessions, and compulsions; reduced norepinephrine neurotransmission is associated with decreased alertness, low energy, problems with inattention, concentration, and cognitive ability; and dysfunctional dopamine activity is implicated in problems of motivation, pleasure, and reward. Every person can vary in the degree to which each neurotransmitter is out of balance, and finding the right drug treatment or nutritional strategy can be a process of trial and error.
Amino Acid Therapy for Depression
Proponents of amino acid therapy for depression believe antidepressant effects can be achieved naturally. Amino acids for depression include tryptophan, which promotes serotonin synthesis, while the amino acids tyrosine and phenylalanine stimulate norepinephrine and dopamine synthesis. Since there is competition for transport of these amino acids in the intestine and at the blood-brain barrier, it is suggested that amino acids be taken on an empty stomach and independently to maximize uptake and conversion to the desired neurotransmitter. As with drug treatments, it may take some trial and error to work out the exact amino acid therapy regimen for depression.
There are several books available on amino acid therapy for depression. In The Mood Cure, author Julia Ross describes how certain amino acids can boost deficient brain chemicals. She advises that amino acids for mood be used in conjunction with other important changes to diet and lifestyle. Also, treatments should just be used to restore balance so duration and dosage should be moderate, a few weeks or months using no more than the recommended amounts. A good starting point would be to use a complete essential amino acid mixture to test if brain balance can be achieved by providing all of the dietary required amino acids used for neurotransmitter synthesis.
All experts agree that combining nutritional supplements with drugs designed for the same purpose is a bad idea. If depression is clinically diagnosed, your doctor should work with you to find the optimal treatment. If you are exploring nutritional approaches to improve mood and energy, then stick with dietary strategies and natural supplements for depression. As we learn more about neurotransmitters and depression, it becomes clear that balance is the keyword for optimal brain function.