Causes of Depression
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Depression is caused by many factors, from the psychological, social, and environmental to the genetic, and metabolic. Thus while it seems like all depression may be the same, perhaps caused by a serotonin deficiency, and therefore requiring treatment with Cymbalta or Prozac, in fact, depression is not ONE illness. It is very important that the causes of depression in your case be identified so you can get proper treatment. Let’s look at the different causes of depression. These causes can be broken up into several categories (listed in no particular order). Usually, several of these categories are operating in any one individual, and using the whole psychiatry method, they should be identified and treated.
- Genetics: There is growing evidence that there may be certain genetic vulnerabilities for depression. These are commonly called SNP’s or single nucleotide polymorphisms. These are parts of the gene that function a bit differently, and are thought to increase vulnerability to disease, and require more nutrients in the diet. An example of a SNP that has been associated with depression and heart disease is the MTHFR SNP, which requires more folic acid in the diet to help certain metabolic pathways (the folate cycle) to function properly.
- Psychology and social factors: People with depression tend to have learned that they can be helpless in certain situations. Helplessness—real or imagined—leads to a state of depression. Helplessness, particularly around core issues (the need to be loved, to be loving, to have a sense of power, success, or control) reduces one’s self esteem. Learned helplessness is a well-researched model of depression. Interpersonal isolation, marital disputes also fall into this category, as does loss of a close relationship (including perceived rejection).
- Sudden and prolonged (days) disruptions in daily rhythms-such as the sleep cycle (e.g., jet lag), or daily routines can contribute to or precipitate a depressive episode.
- Changes in patters of sunlight can precipitate depressive episodes in those sensitive to seasonal depression.
- Nutrition: deficiencies, due to poor diet, poor digestion and absorption, or because of increased need–of a variety of vitamins and minerals (e.g., B vitamins, zinc, magnesium, chromium), amino acids (tryptophan, tyrosine), fatty acids (omega-3 fatty acids DHA and EPA), fat soluble vitamins (Vitamin D, Coenzyme Q 10) can cause or contribute to depression and have been shown to prevent antidepressant response.
- Digestive disorders: Coeliac disease and irritable bowel are associated with depression, quite possibly (at least in the case of gluten sensitivity such as coeliac disease) because they reduce availability of nutrients. Bacterial overgrowth of the small intestine can, as an example, reduce absorption of B12, leading to depression.
- Immune system:Infection and or inflammation (the reaction to injury or infection) are known to increase cytokines (hormones of the immune system) which alter brain chemistry, making it harder for the brain to make serotonin, and changing dopamine levels, and levels of other excitatory neurotransmitters (NMDA/glutamate).Thus any infection or inflammatory condition can precipitate, cause, worsen, or prevent response to standard treatment for depression, including chronic sinusitis, root canal infections, untreated Lyme disease (or any of the co-infections), mononucleosis, chronic inflammatory conditions (e.g. rheumatoid arthritis, lupus), etc. Some infective agents (such as that causing Lyme disease or certain viruses) alter the way the hypothalamus functions, causing hormonal problems that lead to depression.
- Drugs and detoxification:Numerous drugs can cause depression, including a variety of medications for heart disease, antacids (such as Prilosec), antibiotics, anti-seizure medications, benzodiazepines, pain medications, hormones, asthma medications, over-the-counter medications (e.g., diphenhydramine or Benadryl), anti-tumor medications, and even some herbal preparation. Many chemicals in our environment cause damage to our nervous systems (pesticides, mercury), or hormonal and immune systems (e.g., PCB’s).With over 900 new-to-nature chemicals interacting with us and each other, it is inevitable that these will promote all types of illnesses, which then link back to the risk for depression. Chemical exposure in the workplace should always be considered in the evaluation of your depression.
- Mitochondrial dysfunction (mitochondria are the energy factories of all cells) can lead to marked reductions in energy, resulting in what appears to be depression.
- Hormonal problems: any hormonal system, when not functioning properly, can cause a mood disorder. Most commonly the thyroid, adrenal, reproductive (estrogen, progesterone, DHEA, and testosterone) are involved. However, malfunction of the parathyroid, pancreas (insulin), and pineal gland (melatonin) can also contribute to or cause depression.
- Tumors: brain tumors often present with a psychiatric manifestation such as depression. Pituitary tumors (also in the brain) such as microadenomas, disrupt hormonal function and cause or contribute to depression. Of all malignant tumors, pancreatic cancer most commonly presents as depression, accompanied by abdominal pain radiating to the back.
- Sleep disorders: sleep apnea, nocturnal myoclonus, restless legs, decreased REM latency are all associated with depression.
- Cardiovascular disease: reductions in cardiovascular function, oxygenation of the brain, exercise capacity, blood flow to the brain are all associated with depression, and can contribute to or cause depression. Very commonly, stroke and bypass surgery (CABG-or coronary artery bypass surgery) can be followed by depression.
- Miscellaneous: anemia (iron deficiency, B12 deficiency, bleeding, severe lung disease leading to decreased oxygenation of the brain, obesity, Wilson’s disease (error in copper metabolism), and electrolyte abnormalities (potassium, sodium, chloride).