Contributing factors are substances, contexts or conditions that have roles in the causation or promotion of schizophrenia.

Diet and schizophrenia

• Diet is commonly considered the most important mediator of health and disease.
• People with psychosis are more likely to eat quickly, skip breakfast and eat evening snacks (Aucoin, 2020).
• Schizophrenia is more common in industrialized cultures than non-industrialized cultures, suggesting that diet, among other factors, have roles in schizophrenia. (Schizophrenia | Nutrition Guide for Clinicians, n.d.)
• Diets of schizophrenia patients are often poor, and antipsychotic medications can promote weight gain, as well as blood-sugar and blood-lipid issues (Schizophrenia | Nutrition Guide for Clinicians, n.d.).

Psychosis is one aspect of schizophrenia. Several diet-mediated mechanisms have been tied to psychosis. These include (Aucoin, 2020):

• vitamin and mineral insufficiency
• blood sugar dysregulation
• gut microbiome
• oxidative stress
• methylation cycle imbalances
• inflammation
• food sensitivities
• essential amino acid deficiency
• fatty acid deficiency

The Mediterranean diet

• The Mediterranean diet is considered a good model for a healthy diet. It includes foods that are beneficial and reduces or elimates foods that promote mental health issues.
• General components of the mediterranean diet include:
  • plenty of vegetables and fruit
  • healthy fats including olive oil
  • regular consumption of seafood
  • whole grains instead of refined grains
  • poultry, beans, and small amounts of red meat
  • small amounts of dairy (yogurt and cheeses)

Useful Information

Schizophrenia—Symptoms and causes. (n.d.). Mayo Clinic. Retrieved November 3, 2020, from https://www.mayoclinic.org/diseases-conditions/schizophrenia/symptoms-causes/syc-20354443

Mediterranean diet for heart health
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/mediterranean-diet/art-20047801

• Gluten is a general name for proteins found in wheat and related grains. Although many people are not affected by gluten, for others it can cause problems, including schizophrenia.
• 1 in 7 people experience negative effects from eating gluten-containing foods. (Specter, 2014).

Wheat allergy, celiac, and NCGS

• gluten sensitivity (NCGS).
• Only a small amount of people have an antibody-mediated allergy to wheat
• Most people who have issues with wheat react to the gluten component of grains (Specter, 2014).

Some effects of gluten consumption are (Specter, 2014):

• abdominal and muscle pain
• nausea
• diarrhea and constipation
• brain fog
• mood changes

Other effects of gluten include:

• decreased nutrient absorption
• increased digestive tract and systemic inflammation
• damage to digestive tract lining leading to leaky gut
• dysregulation of immune system function (Aucoin et al., 2020).

Celiac disease and NCGS

• Celiac and NCGS are different conditions, but both can affect brain and mental health.

Characteristics of celiac disease

• Mediated by a genetic predisposition
• Exposure to gluten provokes autoimmune reactions that damage absorptive structures in the digestive tract as well as different organs throughout the body

Characteristics of NCGS

• negative response to gliadin and other grain proteins
• over-activated innate immune system
• different antibodies from those tied to celiac disease
• absence of intestinal damage seen in celiac disease

Onset of symptoms after consuming wheat (Schuppan et al., 2015):

• Allergy – minutes to hours
• NCGS – hours to days
• Celiac – days to weeks

Gluten and schizophrenia

• Epidemiological studies show an association between wheat and gluten consumption and schizophrenia (Aucoin et al., 2020).
• Celiac patients have been estimated to be at five times greater risk for becoming schizophrenic (Eaton et al., 2004; Kelly, et al., 2019).
• Leaky gut caused by celiac or NCGS can allow undigested food particles and microorganisms to get into the bloodstream, where they promote inflammation and autoimmune reactions throughout the body, including the brain.
• Patients with celiac and NCGS share similar inflammatory markers with schizophrenics (Jeppesen & Benros, 2019).
• Inflammation is a known promoter of schizophrenia. It affects neurotransmitters, synaptic plasticity, and cortisol levels, which results in alterations to mood, awareness, and behaviour (Khandaker et al., 2015).

Addressing gluten issues

• Avoid all sources of gluten
• Some sources of gluten (Sources of Gluten, n.d.) are: wheat, rye, barley, triticale, malt, brewer’s yeast, wheat starch, pastas, noodles, bread, crackers, baked goods, cereals, sauces and gravy, beer
• “Gluten-free diets represent a potential safe adjunctive therapeutic strategy for a subset of patients with schizophrenia” (Aucoin et al., 2020).

Diagnostic tests to determine likelihood of benefiting from a gluten-free diet can include:

• serum concentrations of IgA and IgG antibodies to glutaminase (AGA)
• tissue transglutaminase (tTG)
• Also see Schizophrenia and exorphins section for more effects of gluten.

What are exorphins?

• Exorphins are short strands of amino acids, absorbed from partially digested food, that bind to opiate receptors in the brain.
• The exorphins gliadorphin and casomorphin are generated from normal digestive breakdown of gluten and casein. Gliadorphin is derived from the gluten component of grains, and casomorphin is derived from the casein component of dairy.
• At normal levels, exorphins have roles in food-seeking and appetite regulation.
• At high levels, exorphins drive addictions and alter sensory perceptions (Pruimboom, & De Punder, 2015), and cause:
  • speech and hearing problems
  • spaciness and “brain fog”
  • near-constant fatigue
  • irritability; aggression and moodiness
  • anxiety and depression
  • sleep problems

Causes of increased brain exorphins

• Leaky gut (increased intestinal permeability) can allow large amounts of exorphins to enter the bloodstream from the digestive track and access the brain.
• The enzyme dipeptidyl peptidase-IV (DPP-IV) breaks down gliadorphin and casomorphin into harmless amino acids. However, DPP-IV function can be inhibited by the gliadin component of gluten. When DPP-IV is inhibited, less gliadorphin and casomorphin is broken down, so more of it reaches the brain.

Drivers of DPP-IV insufficiency include: 

• overconsumption of wheat and milk
• genetic susceptibility
• antibiotics
• gelatin from vaccines
• candida
• mercury and other heavy metals
• pesticides
• nutritional deficiencies

Exorphins and schizophrenia

• Blood and urinary concentrations of exorphins from wheat and dairy have been reported to be higher in schizophrenics (Bressan & Kramer, 2016).
• A diet that excluded grains and milk versus a standard diet, allowed relapsing schizophrenics to be released significantly faster from hospital (Gaby, 2011), implying gliadorphin and casomorphin played a role in the expression of schizophrenic symptoms.

• Caffeine is a molecule that acts as a stimulant in the central nervous system. It is commonly found in coffee, black tea, energy drinks, soda drinks, chocolate, some medications, as well as guarana and yerba maté.

Effects of caffeine

• Effects of excessive caffeine consumption can include nervousness, irritability, palpitations, insomnia as well as increased heart rate, body temperature, blood flow, and blood sugar levels.
• Caffeine depletes nutrients that are important for mental health such as B vitamins, vitamin C, potassium, magnesium, calcium, zinc (Scott, 2011).
• Caffeine increases adrenal production of epinephrine and norepinephrine, which over time, can weaken the adrenal glands (Levi, 1967)
• Excess caffeine makes the way the body responds to hypoglycemia worse (hypoglycemia is a risk factor for schizophrenia).

Caffeine and schizophrenia

• Excessive caffeine consumption has been associated with worsening of psychosis, mania, and unusual thought content (Lucas et al., 1990).
• Restricting caffeine consumption can promote decreased hostility, suspiciousness, anxiety, and irritability in people with psychiatric conditions who drink excessive amounts of coffee (“Effects of Caffeine in Chronic Psychiatric Patients,” 1979).

• Nicotine is a stimulant compound found in tobacco and has been shown to increase heart rate and blood pressure.

Smoking and mental health

• Smoking increases dopamine activity in the brain by increasing its production and decreasing its breakdown (Sagud et al., 2009).
• Smoking increases the risk of panic attacks and panic disorder (Goodwin, Lewinsohn, & Seeley, 2005).

Nicotine and schizophrenia

• Although smoking can temporarily relieve immediate anxiety, chronic smoking can increase chronic nervousness and agitation.
• Smoking is significantly more common in schizophrenics compared to the general population. More than 60% of schizophrenics smoke (Sagud et al., 2009).
• Smoking can increase the amount of antipsychotic medication required by schizophrenics. Medication amounts may need to be reduced if discontinuing smoking (Sagud et al., 2009).

Toxic metals like mercury, lead, and cadmium are pervasive in the environment. 

Toxic metals and mental health

• An abundance of research shows that the accumulation of these metals in the body have negative impacts on health.
• Toxic metals bind tissues and interfere with the functions of essential minerals (Sears, 2018).
• The high level of metabolic activity of the brain and excessive oxidative stress caused by toxic metals, can promote free radical damage to important components and molecules in the brain.
• Toxic metals compete with essential minerals for absorption and transportation, which means poor nutrition increases the risk for toxicity (Sears, 2018).
• The brain is especially susceptible to accumulation and storage of fat-soluble toxic metals because of its high fatty-acid composition (Orisakwe, 2014).

Toxic metals and schizophrenia.

• Toxic metals that have roles in the development or manifestation of schizophrenia include lead, aluminum, cadmium, copper, arsenic.

Addressing toxic metal accumulation

• Environmental and dietary sources of toxic metal exposures need to be identified and removed as much as possible.
• Many patients will improve with a basic protocol of a healthy diet, supplementation of essential nutrients, exercise and rest. Sweating from exercise or sauna can also help remove toxic metals (Sears, 2018).
• The best approach for brain detoxification is conservatively, “with repeated, modest treatments, using multiple agents” (Sears, 2018).
• It is important to work with a practitioner that is trained in detoxification when addressing excessive or chronic heavy metal exposure or accumulation.

Medication-induced nutrient deficiencies and mental health

Many types of medications deplete essential nutrients that have roles in preventing mental health issues. For example:

• Oral contraceptives, antidepressants, decongestants deplete vitamin B6 (Pelton, LaValle, & Hawkins, 2001)
• Corticosteroids, ACE inhibitors and oral contraceptives deplete zinc.  (Scott, 2011)
• The antipsychotic drug chlorpromazine may cause riboflavin deficiency in malnourished people (Pelliccione et al., 1983). Riboflavin deficiency can cause psychiatric symptoms (Zaslove et al., 1983)

Further information

An in-depth examination of common medications and nutrient depletions. (Mohn et al. 2018)

https://doi.org/10.3390/pharmaceutics10010036

Medications and Schizophrenia

Standard schizophrenia treatments use atypical psychotic drugs (APDs) which act primarily on dopamine receptors. These medications typically only partially reduce symptoms.

Some APDs include:

• Aripiprazole
• Clozapine
• Olanzapine
• Quetiapine
• Risperidone

Additional drugs are often required to address the extrapyramidal and parkinsonian symptoms caused by the APDs. These symptoms can include:

• tremors
• muscle spasms
• rigidity
• slowness
• involuntary movements

Schizophrenic patients taking one or more of the APDs can experience a state of unease or dissatisfaction (Horrobin, 2001), and are at higher risk for brain damage, heart arrhythmias, diabetes, weight gain, sexual dysfunction, and akathisia (uncontrollable urge to move).

Tranquilizer psychosis and tardive dyskenesia

• The “tranquilizer psychosis” is a term used to describe the mental effects — lethargy, loss of interest, difficulty in concentration, loss of libido, tardive dyskinesia —which the antipsychotic drugs exert on the patient.
• Tardive dyskinesia is an involuntary neurological disorder caused by dopamine-affecting medications, resulting in uncontrollable, erratic or repetitive muscular movements.

Orthomolecular support and medications

• According to Dr. Hoffer, less than 10 percent of schizophrenic patients treated with drugs alone recover (Gaby, 2011).
• By combining both nutrients and drugs patients can take advantage of both therapies and minimize the disadvantages. Patients started on both will respond much more quickly.
• The use of orthomolecular nutrients in conjunction with medications can reduce medication need, reduce side effects, and increase chances for a full recovery
• Results of orthomolecular treatments may be seen after one to two months, but it can take 3 to 6 months to see clinical benefits. With chronic schizophrenia, results may take years to see benefits.

Decreasing medications

• “Antipsychotic drugs convert a natural psychosis to a different type of psychosis. Consequently, any improvement resulting from the use of diet and nutritional supplements may not become evident until medication doses are decreased” (Gaby, 2011).
• Medications should not be discontinued without the cooperation of the patient’s psychiatrist, and even then they may need to be reduced very slowly, over many months to several years.

• Schizophrenia symptoms can be caused or promoted by nutrient deficiencies or dependencies.

Nutrient DEFICIENCY:

• Nutrient deficiency is when the minimum amounts of nutrients needed for normal body function are not met by diet
• A nutrient deficiency results in depletion of nutrients in body tissues, and changes to mental and physical functioning from diet, medications.

Nutrient DEPENDENCY:

• The metabolic need for a nutrient exceeds what can be supplied by diet and results in impaired biochemical processes and functions.
• A nutrient dependency results from long-term environmental and genetic stressors.

Food allergies and the brain

• Allergic reactions may play a major role in almost every psychiatric syndrome, including mood disorders, schizophrenia, the anxiety states, and children with learning and/or behavioral disorders.
• Food allergies and sensitivities that affect the brain can be referred to as “cerebral allergies”. Cerebral allergies encompass more than antibody-antigen reactions.

Cerebral allergies are mediated by:

• direct biochemical effects of substances found in food or drink, for example caffeine, alcohol, and sugar
• hidden or delayed allergic reactions to food or drink, for example wheat, milk, corn, and egg

Foods commonly associated with allergies (Prousky, 2015):

• dairy products
• wheat, rye, barley
• eggs
• pork, beef, seafood
• soy
• corn, tomato
• citrus fruits
• nuts, peanuts
• chocolate
• coffee, tea
• sugar
• yeast

Food allergies and schizophrenia

• Food allergy reactions that affect the brain may be a contributor to psychosis.
• Schizophrenic patients have a high prevalence of food antibodies (Gaby, 2011)
• A study by Kinnell et al. (1982) showed that 37% of schizophrenics, when tested for wheat, oats, gluten, chicken, beef, and milk protein, had antibodies for one or more of the foods.
• Antibodies to certain foods may cross-react with brain tissue in susceptible people and negatively impact brain function (Gaby, 2011)
• Anti-brain antibodies in a study by Pandey et al (1981) were absent in healthy controls, but were present in 48% of schizophrenics.

Foods that have been reported to frequently cause symptoms in people with schizophrenia include (Philpott, 1976):

• wheat
• dairy
• corn
• coffee
• legumes

Identifying food allergies

• Common symptoms include: a history of many colds, runny noses, earaches, and tubes in the ears.
• Allergic children may have red ears and allergic “shiners” (dark circles under the eyes caused by congestion)
• Often allergic patients love what they are allergic to and have great difficulty in eliminating these foods from their diet.

Addressing food allergies

• Food allergies can often be identified by following an elimination diet, then testing individual foods one at a time.
• Once identified, allergic foods need to be eliminated from the diet.
• When allergic substances are eliminated, it may take one to six months to become free of the food-allergy effects.
• Food allergies often point to leaky gut.
• A digestive healing protocol should be considered as part of addressing food allergies in the context of schizophrenia.

Adrenochrome and schizophrenia

• Adrenochrome is a toxic derivative of adrenaline, which is thought to have a role in producing the psychotic features of schizophrenia.
• People with schizophrenia can have a reduced capacity to degrade and remove adrenaline from their body, which makes them more susceptible to its negative effects.

When healthy volunteers were given adrenochrome in a study, they experienced (Gaby, 2011):

• changes in visual perception, thinking, and mood
• hallucinations
• psychotic reactions identical to schizophrenia

Adrenolutin, which is derived from adrenochrome, has also been shown to promote hallucinations.

Addressing adrenochrome

See vitamin B3 and vitamin C sections.

The microbiome

• The human microbiome is made up of 10-100 trillion microbial cells consisting of bacteria, fungi, and viruses, among many others.
• The microbiome also includes the genes contained by these cells (Ursell et al., 2012).
• The composition of the microbiome is influenced by changes in diet and health (Quigley, 2013).

The microbiome is affected by:

• antibiotics
• infections
• dietary sucrose (sugar and starch consumption)
• dietary chemicals – including pesticides, additives and preservatives
• medications – NSAIDs, Prednisone, OCP
• food intolerances 
• location of birth
• the birthing process 
• formula feeding

The gut-brain axis and mental health

• The gut-brain axis includes the brain, spinal cord, autonomic nervous system (sympathetic, parasympathetic and enteric nervous systems), and the hypothalamic-pituitary–adrenal (HPA) axis (Dinan et al., 2015).
• Mental health conditions affected by the gut-brain axis include anxiety, depression, autism, obsessive compulsive disorder, and schizophrenia.

Assessment of the microbiome in the context of schizophrenia suggests that schizophrenia is associated with (Nguyen, Kosciolek, Eyler, Knight, & Jeste, 2018):

• reduced microbial diversity
• increased intestinal inflammation and permeability
• microbial populations that are associated with depressive and psychotic symptoms, compromised physical health and sleep

The microbiome and schizophrenia

• The microbiome may promote the production of the beneficial protein brain-derived neurotrophic factor (BDNF). BDNF is an important growth factor for neurons and has a role in the function of NMDA neurotransmitter receptors – both of which have a well-established relationship with schizophrenia pathology.

Candida and schizophrenia

Candida is a type of yeast and the most common cause of human fungal infections (Manolakaki et al., 2010).

Schizophrenia symptoms have been reported to be improved by antifungal medications and treatments (“Mold, Mycotoxins & Autoimmunity,” n.d.).

“Candidiasis should be considered as a possible contributing factor in schizophrenic patients who have had recurrent vaginal yeast infections or a history of treatment with antibiotics, oral contraceptives, or systemic glucocorticoids” (Gaby, 2011).

Hypoglycemia is a condition of abnormally low levels of blood sugar.

Causes of hypoglycemia include (Hypoglycemia – Symptoms and Causes, n.d.):

• diabetes
• medications
• excessive alcohol consumption
• liver and/or kidney disorders
• overproduction of insulin

Reactive hypoglycemia – overview

• Consumption of a high-carbohydrate meal or drink causes a rapid rise in blood glucose.
• The high glucose causes the pancreas to release an abnormally high amount of insulin into the blood. This causes an abrupt drop in blood glucose.
• The excessive drop in blood sugar triggers the release of the hormones epinephrine and norepinephrine, which in turn, trigger the “fight or flight” response.
• The “fight or flight” response will show as hunger, irritability, sweating, palpitations, and anxiety.

Reactive hypoglycemia and schizophrenia

• Reactive hypoglycemia can trigger or worsen symptoms such as anxiety, depression, fatigue, and paranoia (Gaby, 2011)

Identifying hypoglycemia

Signs of hypoglycemia:

• tendency to crave sweets
• consuming sugar or refined starches temporarily reduces hypoglycemia symptoms
• symptoms worsen in the late morning or late afternoon
• mental and anxiety symptoms occur after fasting, late at night, or first thing in the morning (Eaton & Konner, 1985)

Symptoms of hypoglycemia (Hypoglycemia – Symptoms and Causes, n.d.):

• irregular or fast heartbeat
• fatigue
• pale skin
• shakiness
• anxiety
• sweating
• hunger
• irritability
• tingling or numbness of the lips, tongue or cheek

Typical medical tests to assess blood-sugar metabolism are:

• fasting glucose
• HbA1c
• insulin, cortisol, ketone bodies, lactic acid, free fatty acids, and thyroid hormone may also be included (Mandal, 2019)

• Homocysteine is an amino acid that is made by the body and is also supplied by food.
• Deficiencies of folate, vitamin B12, and vitamin B6 can result in increased homocysteine levels.

Homocysteine and schizophrenia

• Many schizophrenia patients have elevated levels of homocysteine.
• Elevated homocysteine levels are associated with mental issues including mild cognitive impairment, Alzheimer’s Disease, Parkinson’s Disease, depression, and schizophrenia (Kim & Moon, 2011)
• Supplementation with vitamin B6, vitamin B12, and folic acid were shown to lower homocysteine levels and improve symptoms of schizophrenia compared with a placebo in a study by Levine et al. (2006)

• Histadelia is a clinical syndrome that is promoted by elevated histamine levels.

Histadelia and schizophrenia

• Dr. Pfeiffer (1975) stated that around 20% of schizophrenics are estimated to have histadelia, and often suffer from suicidal depression.

Vitamin B3,vitamin C, and histadelia

• The nicotinic acid form of vitamin B3, niacin, decreases tissue stores of histamine, which in turn helps to lower blood histamine levels.
• The nicotinamide form of vitamin B3, niacinamide,  helps with histadelia by inhibiting mast cell histamine release, which happens during an allergic response.
• Both the nicotinic acid and the nicotinamide forms of vitamin B3 may be required to address the nicotinamide adenine dinucleotide (NAD) deficiency. NAD deficiency is considered to be the driver of histadelia.
• Vitamin C has been shown to lower blood histamine levels. However people with schizophrenia may have impaired vitamin C metabolism, and a resulting increase in circulating histamine.

• Histapenia is a clinical syndrome that is promoted by low histamine and high serum copper levels.
• Histapenia is characterized by high blood copper and low histamine values. 

Histapenia and schizophrenia

• Dr. Pfeiffer (1975) stated that around 50 percent of schizophrenics have histapenia, are usually over-stimulated, paranoid, and  suffer from hallucinations.

Addressing histapenia

When treated for histapenia by Dr. Pfeiffer, patients had the following time sequence of improvement:

• In the first month, sweaty palms, racing thoughts, insomnia and hypomania tend to diminish.
• By one year, the hallucinations, obesity and paranoid ideas diminish.

Histapenic patients respond well to supplementation of Vitamin B3, folic acid, and Vitamin B12.

Take caution when supplementing vitamins while taking antipsychotic medications

• Doses larger than 2 mg/day of folate, together with antipsychotic medications, can cause involuntary muscle twitching and seizures.
• Excessive amounts of folic acid and vitamin B12 can increase histamine levels too much, increasing the risk of depression – so blood histamine levels should be monitored during this treatment. (Gaby, 2011)

• Pyrroles are a by-product of hemoglobin production and are normally excreted in the urine.
• Pyroluria is a condition of overproduction of pyrroles (McGinnis 2008a, 2008b).
• Excess pyrroles bind vitamin B6 (pyridoxine) and zinc, removing them from the bloodstream.

Signs of high amounts of kryptopyrrole are most prevalent in adolescents and children and include: 

• white areas in their fingernails
• fragile nails
• pain in the joints often the knees
• lack of pigment in the skin
• skin infections and acne
• sometimes morning nausea
• poor dream recall
• insomnia
• psychiatric symptoms

Pyroluria and mental health

The mental symptoms of pyroluria are largely related to zinc and vitamin B6 deficiencies. 

Mental symptoms of these deficiencies include:

• anxiety and depression
• mood swings
• poor stress control
• severe inner tension
• episodic anger
• nervousness
• poor short-term memory

Addressing pyroluria

• Pyroluria can be objectively diagnosed by elevated levels of HPL (Hydroxyhemopyrrolin-2-one) when measured by the kryptopyrrole quantitative urine test.
• The amount of kryptopyrrole can fluctuate dramatically. Stress, illness, and injury increase levels.
• For optimal test results, the urine should be collected during a period of increased stress.

Supplementation support for addressing pyroluria (Greenblatt, 2018):

• 200-800 mg of vitamin B6 in the pyridoxal-5-phosphate form
• 25–100 mg of zinc

Dr. Jonathan Prousky (2006) stated, “Although I could test for this compound [HPL], I choose not to, since these nutrients are inexpensive and have minimal side effects. The daily dosages I routinely start with are 250 mg of pyridoxine and 50 mg of zinc”.

Thyroid hormones and the brain

• Thyroid hormones have important roles in brain health and function. They are mediators of neuronal cell migration, differentiation, signalling, and brain maturation (Bernal, 2005). Thyroid hormones are also important for axonal outgrowth, dendritic branching and myelination (Calzà, Fernández & Giardino, 2015).
• Thyroid hormones affect the amount of dopamine receptors that are made, as well as affecting the formation of dopamine, norepinephrine and epinephrine.
• Thyroid hormones also have roles in regulating serotonin and glutamate levels. (Santos et al., 2012)

The hypothyroid state 

Hypothyroidism is a state of decreased effect of thyroid hormones on the body. Common symptoms of hypothyroid include: 

• cold intolerance
• low body temperature
• weakness
• low energy or fatigue
• easy weight gain
• hair loss
• pain
• headache
• PMS
• insomnia
• indigestion and constipation
• elevated cholesterol
• frequent infections

Mental symptoms of hypothyroid include (Pataracchia, 2008; Hoffer, 2001a):

• impaired cognition
• anxiety or panic
• depression
• irritability
• poor memory or concentration

Causes of hypothyroid

• Insufficient precursor molecules for thyroid hormone, especially iodine and tyrosine.
• Molecules like bromine and genistein can compete with iodine and tyrosine for absorption and incorporation into thyroid hormones.
• Autoimmune action against thyroid enzymes and TSH receptors reduce thyroid function.
• Decreased conversion of T4 to the more metabolically active form T3 can result from (Hoffer, 2001a) stress, oxidative stress, environmental toxin exposures, liver and kidney issues, calorie restriction, sleep deprivation, and excessive exercise.
• Thyroid hormone receptors on target cells can become resistant to T3 due to environmental toxins, as well as autoimmune, genetic, and other factors.

Hypothyroid in the brain

• Conversion of T4 to T3 can be inhibited in the brain by cortisol. Cortisol levels in schizophrenics are often elevated, especially when they are experiencing stress.

Hypothyroid and schizophrenia

• Hypothyroidism affects systems involved in schizophrenia including:
  • metabolism of serotonin, dopamine, glutamate and GABA
  • myelination and regulation of inflammation (Santos et al., 2012).
• Hypothyroidism is common in schizophrenia patients (Santos et al., 2012). Low thyroid symptoms are often seen in patients with psychosis, and schizophrenics can relapse when thyroid function is low (Pataracchia, 2008).
• A study by Themeli, Aliko, & Hashorva (2011) showed that 25% of chronic schizophrenic patients had evidence of thyroid dysfunction.
• Thyroid function is often reduced as a result of taking psychiatric medications (Vickery, Mathews, & Vickery, 2019).