Biochemical causes of depression

The problem with using SSRI drugs to overcome the symptoms associated with low serotonin levels is that although they do increase the activity of serotonin, they do not replenish serotonin levels.

by Dr. Mark Force — 

Certain distinct biochemical imbalances that trigger depression have been found to respond well to diet and nutritional supplementation. Different types of depression have different symptoms and underlying causes, including primary biochemical depression, serotonin deficiency, dopamine deficiency, high norepinephrine/epinephrine ratio, GABA deficiency and histamine excess.

This article will discuss the most common primary causes of depression — serotonin and dopamine deficiency. Future articles will cover the less common primary causes, and the secondary causes as well.

Serotonin deficiency

Serotonin deficiency is characterized by anxiety and depression. Low serotonin levels in the body also may cause migraine, irritable bowel syndrome, fibromyalgia and bipolar disorder (manic depression). Carbohydrate cravings and poor regulation of appetite also have been associated with low serotonin levels.

Since serotonin is the precursor for melatonin production in the brain, and melatonin regulates sleep, low serotonin levels are associated with insomnia and inefficient sleep that lacks the essential REM (rapid eye movement) stage.

This is commonly treated with selective serotonin reuptake inhibitor (SSRI) drugs such as Prozac, Effexor, Celexa, Lexapro, Paxil or Zoloft. Interestingly, these drugs are typically prescribed based on history only. Rarely are actual serotonin levels tested to determine if support of serotonin is appropriate or not, even though this testing is available.

The problem with using SSRI drugs to overcome the symptoms associated with low serotonin levels is that although they do increase the activity of serotonin, they do not replenish serotonin levels. This can account for a common problem associated with SSRI medication, whereby it becomes ineffective over time.

Serotonin deficiency is commonly caused by a mostly cooked diet that is deficient in the amino acid tryptophan. For tryptophan to be converted to serotonin, vitamin B6 must be sufficiently present, but it is broken down by cooking.

Dopamine deficiency

Dopamine deficiency can cause depression that is characterized by a marked lack of energy and motivation, along with mental dullness. Optimal dopamine levels lead to a natural, balanced sense of energy, excitement and mental focus. High dopamine levels can lead to obsessive, compulsive and aggressive behaviors. Low dopamine is associated with poor attention and focus, hyperactivity, memory deficit, cravings, addictive behavior, and poor fine motor control and coordination.

Symptoms of people with low dopamine levels include low metabolism, fatigue, inability to concentrate, poor short-term memory, impaired learning, low sex drive, forgetfulness and attention deficit disorder. Often they will sleep long hours and still feel tired. Usually their minds wander, they have difficulty making decisions, and lack will and discipline.

Ideally, a diagnostic work-up for depression should include a comprehensive physical exam and lab tests to determine the factors that might be causing the depression. Recently, lab tests have become available that can measure neurotransmitter levels. Clinical nutrition also can produce measurable changes in serotonin and dopamine balance.

Mark Force, D.C., is a chiropractic physician at The Elements of Health in North Scottsdale, Ariz. He practices Functional and natural healthcare and is the author of Choosing Health: Dr. Force’s Functional Selfcare Workbook. 480-563-4256 or theelementsofhealth.com.

Reprinted from AzNetNews, Volume 26, Number 3, June/July 2007.