Research: Depression and Mercury Toxicity
I. Introduction
According to Dr. Gerald Klerman, based on National Institute of Health studies there has been a huge increase (over 500 %) in the rate of depression and chronic neurological problems over the last 3 decades. A random sample of Oregon high school students found that over 16% had been diagnosed with depression. According to ECA samples, otherwise healthy people born in recent decades face a 10 fold increase in incidence of major depressive episodes compared to those sampled who were born in earlier decades. Over 6 million Americans over 65 suffer from major depression while another 5 million suffer from depressive symptoms.
Several factors appear to be contributing to this:
1. Neurological birth defects and developmental conditions due to increased levels of vaccinations, foetal exposure to alcohol, tobacco smoke, drugs, toxic metals such as lead, mercury and cadmium in addition to other neurotoxic chemicals such as pesticides and nitrates and other endocrine system/hormonal system disrupting chemicals such as dioxins. Studies by the National Academy of Sciences indicate that these affect close to 40% of all children in the U.S., more in some populations than others.
2. Changes in dietary habits resulting in nutrient, vitamin, and mineral deficiencies or imbalances and blood sugar imbalances (594), and increased consumption of inflammatory excitotoxins such as aspartame, MSG, and high fructose corn syrup.
3. Stress in family and workplace environments.
Groups of primary care patients aged 18 - 65 years from 333 randomly chosen public or private clinics throughout the whole country of Poland, totalling 7,289, coming for a regular visit were asked to participate in a study of the prevalence of depressive disorders. 71% of the sample was female. All patients filled in the Beck Depression Inventory (BDI). The prevalence of depressive disorders in the whole sample was 23.3%.
The number of people with anxiety disorders is close to the number with mood disorders. The primary types of anxiety disorders are phobias, panic attacks, generalised anxiety disorder (GAD), and obsessive-compulsive disorder (OCD). At least 20 million people are affected at some time by these conditions. Similar large numbers are affected by attention disorders, including attention deficit hyperactive disorder (ADHD), dyslexia, and schizophrenia.
II. Causes of depression and anxiety
There appears to be both a psychological/mind basis as well as physical/chemical basis for depression and anxiety. Nutritional deficiencies, environmental factors, methylation deficiencies, hormonal imbalances, and stress clearly can lead to depression and anxiety, but they also facilitate psychological factors. Based on clinical experience, anxiety and hyperventilation and panic attacks appear to often be related to a person burying their feelings about their circumstances. Depression often occurs where a person has suppressed anger, anger turned inward. Dealing with nutritional deficiencies and environmental factors, along with being honest with yourself, acknowledging anger or feelings rather than assigning blame, and doing what makes you feel good usually leads to reduced depression or anxiety.
The levels of brain neurotransmitters such as dopamine, norepinephrine, and serotonin, appear to be major factors in controlling moods, and appear to be affected by lifestyle, diet, philosophy, and environmental factors. Some are more susceptible to depression than others, and thus more affected by diet and environmental factors.
Inflammatory processes and depression
Chronic or acute brain inflammation appears to be a primary factor in depression. The brain is very sensitive to inflammation. Disturbances in metabolic networks: e.g., immuno-inflammatory processes, insulin-glucose homeostasis, adipokine synthesis and secretion, intra-cellular signalling cascades, and mitochondrial respiration have been shown to be major factors in depressive disorders and other chronic neurological conditions.
Inflammatory chemicals such as mercury, aluminium, and other toxic metals as well as other excitotoxins including MSG and aspartame cause high levels of free radicals, lipid peroxidation, inflammatory cytokines, and oxidative stress in the brain and cardiovascular systems. Over-exposure to heavy metals such as lead and mercury have also been shown to induce anxiety or depression.
Oxidative damage and depression
Studies have found that oxidative stress from reactive oxygen species (such as caused by mercury and toxic metals) causes increased insulin resistance, whereas reducing reactive oxygen species lowers insulin resistance. Insulin resistance has been found to be a significant factor in such conditions as metabolic syndrome, cognitive decline, cardiovascular disease, depression and cancer.
Nitric oxide related toxicity caused by peroxynitrite formed by the reaction of NO with superoxide anions, which results in nitration of tyrosine residues in neurofilaments and manganese Superoxide Dismustase (SOD) has been found to cause inhibition of the mitochondrial respiratory chain, inhibition of the glutamate transporter, and glutamate-induced neurotoxicity involved in ALS.
Metal toxicity and depression
Mercury and cadmium inhibit magnesium and zinc levels as well as inhibiting glucose transfer. Reduced levels of magnesium and zinc are related to metabolic syndrome, insulin resistance, and brain inflammation and are protective against these conditions. These are additional mechanisms by which mercury and toxic metals are factors in metabolic syndrome and insulin resistance and conditions such as diabetes and depression.
As documented later, for those who have several amalgam fillings, replacement of the amalgam greatly lowers mercury and toxic metal exposure, lowers reactive oxygen species and related damage, and brings significant improvement in the health of people with conditions caused by oxidative damage and insulin resistance. It has also been documented that supplementation with antioxidants such as green tea extract, bilberries, curcumin, N-acetyl-cysteine, etc. and supplements such as DHEA, Goat’s Rue, cinnamon, quercetin, and vanadyl sulphate reduces inflammatory cytokine effects and lowers insulin resistance.
Mercury and other toxic metals inhibit astrocyte function in the brain and CNS, causing increased glutamate and calcium related neurotoxicity. Mercury and increased glutamate activate free radical forming processes like xanthine oxidase which produce oxygen radicals and oxidative neurological damage.
These inflammatory processes damage cell structures including DNA, mitochondria, and cell membranes. They also activate microglia cells in the brain, which control brain inflammation and immunity. Once activated, the microglia secrete large amounts of neurotoxic substances such as glutamate, an excitotoxin, which adds to inflammation and stimulates the area of the brain associated with anxiety. Inflammation also disrupts brain neurotransmitters resulting in reduced levels of serotonin, dopamine, and norepinephrine. Some of the main causes of such disturbances that have been documented include vaccines, mercury, aluminium, other toxic metals, MSG and aspartame.
Thyroid function and depression
Hormone imbalance has been found to be a common factor in depression. Imbalances in DHEA and cortisol may underlie depression, particularly when stress and obesity are present, and thyroid imbalances have also been found to cause depression. Oestrogen imbalances in post-menopausal women, low testosterone levels in some men, low DHEA levels, and hypothyroid conditions have been found to be common factors in depression. Subclinical hypothyroidism and/or the presence of thyroid peroxidase antibodies (TPOAb) has been found to be associated with sub-fertility, infertility, spontaneous abortion, placental abruption, preterm delivery, gestational hypertension, pre-eclampsia, postpartum thyroid dysfunction, depression (including postpartum depression), and impaired cognitive and psychomotor child development. It is recommended to suspect thyroid pathology if such conditions are present.
Most studies support a relationship between thyroid state and cognition, particularly slowed information processing speed, reduced efficiency in executive functions, and poor learning. Furthermore, hypothyroidism is associated with an increased susceptibility to depression and reductions in health-related quality of life. Controlled studies suggest that cognitive and mood symptoms improve with thyroid treatment, though the data are limited by diverse treatment methodologies.
Functional neuro-imaging data provide support for the mood and cognitive findings and treatment reversibility for both overt and subclinical hypothyroidism. 94 patients with subclinical hypothyroidism and a control group were evaluated to determine the prevalence of psychiatric disorders. The prevalence of depressive symptoms based on Beck's Scale among subclinical hypothyroidism patients was about 2.3 times higher than among controls (45.6% v 20.9%, p = 0.006). Anxiety symptoms were also more frequent in the hypothyroid group.
Postpartum thyroiditis
Postpartum thyroiditis (PPT) is the occurrence, in the postpartum period, of transient hyperthyroidism and/or transient hypothyroidism, with most women returning to the euthyroid state by 1 year postpartum. However PPT frequently reoccurs in subsequent pregnancies and approximately 25% of women with a history of PPT will develop permanent hypothyroidism in the ensuing 10 years. The mean prevalence of PPT in 2 studies was 7.5%. Postpartum thyroiditis is an autoimmune disorder, and thyroid antibody-positive women in the first trimester have a 33% to 50% chance of developing thyroiditis in the postpartum period. There was a 70% chance of developing recurrent PPT after a first attack, and a 25% risk even in women who were only anti-TPO positive without thyroid dysfunction during the first postpartum period. For this group of women with PPT, 46% had postpartum depression in one or more pregnancies.
In a study of effects of hypothyroid or thyroiditis during pregnancy, infants of women with hypothyroxinaemia at 12 weeks' gestation had significantly lower scores on the Neonatal Behavioural Assessment Scale orientation index compared with normal subjects. Regression analysis showed that first-trimester maternal free thyroid hormone was a significant predictor of orientation scores. This study confirmed that maternal hypothyroxinaemia constitutes a serious risk factor for neuro-developmental difficulties that can be identified in neonates as young as 3 weeks of age
Because of such evidence, in November 2002, the American Association of Clinical Endocrinologists (AACE) recommended screening all women considering conception and/or all pregnant women in the first trimester for thyroid dysfunction.
For a group of women with PPT, 46% had postpartum depression in one or more pregnancies.
As will be shown, there is considerable evidence that depression/neurological problems can be caused by many physiological problems related to past toxic exposures or combinations of these. Where physiological problems are contributing factors, determination of the underlying cause from assessing the person’s past medical history, diet, blood tests, hair tests and so on can be useful to identifying and correcting any nutritional deficiencies or imbalances or identifying other problems to be dealt with. There is considerable evidence mercury exposure is among the most common significant exposures that commonly cause such effects, although many are also exposed to lead, arsenic, and pesticides that have similar effects and effects are synergistic or cumulative.
III. Mercury exposure levels from amalgam and other sources
Amalgam fillings have been documented to leak significant levels of mercury continuously due to high vapour pressure of mercury and galvanic action between mixed metals in the mouth. The average person with several fillings gets significant exposure of mercury daily, much more than from any other source and more than that prescribed by U.S. Government health guidelines.
Mercury in pregnant women is also documented to cross the placenta and accumulate in the foetus to levels higher than in the mother. Since mercury from amalgam fillings of a mother is also transmitted to nursing infants in significant amounts, mercury from their mom’s dental fillings has been found to be the largest source of mercury to the foetus and a significant source of mercury in infants, which has produced developmental problems that affect children later in life.
Young children also have been receiving significant levels of mercury (thimerasol which is used as a preservative in vaccines) and large numbers have been found to be significantly adversely affected because of receiving larger numbers of vaccinations, especially at very early ages before the blood-brain barrier matures. People also get significant prenatal and postnatal exposures to other toxic metals such as lead, arsenic, cadmium and aluminium which have also been found to commonly cause significant neurological effects.
The top 3 toxic substances affecting large numbers of people in the U.S. adversely according to the US Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) are mercury, lead, and arsenic.
IV. Toxic and immune reactive effects of mercury
Mercury:
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Is neurotoxic (kills or damages brain and nerve cells)
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Generates high levels of reactive oxygen species (ROS) and oxidative stress and depletes glutathione and thiols causing increased neurotoxicity from interactions of ROS, glutamate, and dopamine
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Kills or inhibits production of brain tubulin cells
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Inhibits production of neurotransmitters by inhibiting: calcium-dependent neurotransmitter release, dihydroteridine reductase, nitric oxide synthase, blocking neurotransmitter amino acids, and effecting phenylalanine, tyrosine and tryptophan transport to neurons.
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Causes systemic methylation deficiencies, which are documented to commonly be a factor in chronic conditions such as depression and autism.
Numerous studies have found long-term chronic low doses of mercury cause neurological, memory, behaviour, sleep, and mood problems. Neurological problems are among the most common and serious effects of mercury, and include memory loss, moodiness, depression, anger and sudden bursts of anger or rage, self-effacement, suicidal thoughts and lack of strength or force to resolve doubts or resist obsessions or compulsions.
Many studies of patients with major neurological diseases have found evidence amalgam fillings may play a major role in development of conditions such as:
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Depression
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Schizophrenia
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Memory problems
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Serious neurological diseases such as MS, ALS, Parkinson’s and Alzheimer’s diseases ... (continued - see below)
Further resources
This is a SAMPLE, for the fully referenced PDF version of this research article click Depression and Mercury Toxicity. Many other research papers are also available on the Research page.
The issue of chronic mercury poisoning from dental amalgam fillings and a detoxification programme are outlined in The Natural Recovery Plan book.
"People affected by chronic fatigue syndrome will find the links made by this book between their condition and a range of medical/dental, environmental and emotional factors intriguing and potentially life-changing".
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