Inflammation

• Brain fog
• Poor attention and concentration
• Poor memory
• Depression
• Mood swings
• Anxiety
• Poor sleep
• Addiction
• Exhaustion

• Aches and pains
• Stiffness (when joints and muscles are affected)
• Heat and swelling
• Redness
• Change in bowel movements (when digestion is affected)
• Headaches (common in chronic inflammation)

Neuro-inflammation can be caused by traumatic brain injuries (for example in a car accident) or are correlated with brain infections or autoimmune disease.

In these circumstances, activated central nervous system (CNS) immune cells and the blood-brain barrier (BBB) coordinate the production of cytokines — chemicals involved in inflammation, and other chemical messengers — which directly influence brain function and act on specific receptors of the brain.Wohleb, E. and Godbout, J. (2013). Basic Aspects of the Immunology of Neuroinflammation. Modern Trends in Pharmacopsychiatry, 28, pp. 1-9. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25224887 [accessed 1 Nov. 2017].

Neuro-inflammation is implicated in various psychiatric disorders such as:

• Depression
• Bipolar disorder
• Schizophrenia
• Obsessive-compulsive disorder
• Parkinson’s disease

Chronic neuro-inflammation, is implicated in neurodegenerative disease such as Alzheimer’s disease and declines in cognitive function.

There is strong evidence linking depression to inflammation, Diniz, B. S., Butters, M. A., Albert, S. M., Dew, M. A. and Reynolds, C. F. (2013). Late-life depression and risk of vascular dementia and Alzheimer’s disease: systematic review and meta-analysis of community-based cohort studies. [online] The British Journal of Psychiatry, 202 (5), pp. 329–335. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23637108 [accessed 1 Nov. 2017]. though it’s not clear whether inflammation contributes to depression, or whether depression contributes to inflammation.

• Studies demonstrate that, when compared to non-depressed patients, depressed patients consistently demonstrate all the cardinal features of inflammation Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
• There is a strong association between inflammatory markers and individual depressive symptoms such as fatigue, cognitive dysfunction, and impaired sleep

Lypopolysaccharides (LPS) which are components of bacteria in the gut, are one of the major causes of inflammation. LPS can get into the bloodstream when there is leaky gut, and can cause systemic inflammation, where it can cause behavioural symptoms overlapping with those of major depression Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].

There is also a link between depression, inflammation and oxidative pathways. Inflammation and oxidation are often seen as ‘essential partners’ in mental health issues.Parletta, N., Milte, C. M. and Meyer, B. J. (2013). Nutritional modulation of cognitive function and mental health. [online] The Journal of Nutritional Biochemistry, 24 (5), pp. 725–43. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23517914 [accessed 1 Nov. 2017].

• Depression is associated with a chronic, low-grade inflammatory response Rawdin, B. J., Mellon, S. H., Dhabhar, F. S., Epel, E. S., Puterman, E., Su, Y., … Hamilton, S. P. (2013). Dysregulated relationship of inflammation and oxidative stress in major depression. [online] Brain, Behavior, and Immunity, 31, pp. 143–52. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23201587 [accessed 1 Nov. 2017]., Berk, M., Williams, L. J., Jacka, F. N., O’Neil, A., Pasco, J. A., Moylan, S., … Byrne, M. L. (2013). So depression is an inflammatory disease, but where does the inflammation come from? [online] BMC Medicine, 11(1), p. 200. Available at: https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-200 [accessed 1 Nov. 2017].
• Depression is associated with elevated cytokines which mediate the body’s innate immunity and their receptors in blood and cerebrospinal fluid (CSF) Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
• There is a link between depression and premature mortality in chronic diseases such as cancer and heart disease Fagundes, C. P., Glaser, R., Hwang, B. S., Malarkey, W. B. and Kiecolt-Glaser, J. K. (2013). Depressive Symptoms Enhance Stress-induced Inflammatory Responses. [online] Brain, Behavior, and Immunity, 31, pp. 172–6. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3518610/ [accessed 1 Nov. 2017].
• Depression is associated with an increase in inflammatory markers such as acute phase proteins, chemokines, adhesions molecules and anti-inflammatory mediators such as prostaglandins Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
• Depression activates cell-mediated immunity (the part of the immune system not associated with antibodies and which is known as the body’s adaptive immunity) Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
  • Activation of cell-mediated immunity refers to activation of the T-cells of the immune system Berk, M., Williams, L. J., Jacka, F. N., O’Neil, A., Pasco, J. A., Moylan, S., … Byrne, M. L. (2013). So depression is an inflammatory disease, but where does the inflammation come from? [online] BMC Medicine, 11(1), p. 200. Available at: https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-200 [accessed 1 Nov. 2017]., Rawdin, B. J., Mellon, S. H., Dhabhar, F. S., Epel, E. S., Puterman, E., Su, Y., … Hamilton, S. P. (2013). Dysregulated relationship of inflammation and oxidative stress in major depression. [online] Brain, Behavior, and Immunity, 31, pp. 143–52. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23201587 [accessed 1 Nov. 2017].
• Depression is associated with activation of the compensatory anti-inflammatory reflex system (CIRS)
  • CIRS is a system that controls acute inflammation and limits an overzealous acute inflammatory response
  • This is achieved by a number of methods, and includes dampening cytokine activity and therefore reducing inflammation

Research has provided evidence for depression-inflammation relationships developing early in life. There appears to be a circular relationship between depression and inflammation in children.

• Children with higher inflammatory cytokine levels were more likely to be depressed at age 18 compared with those with lower cytokine levels Kim, J.-W., Szigethy, E. M., Melhem, N. M., Saghafi, E. M. and Brent, D. A. (2014). Inflammatory markers and the pathogenesis of pediatric depression and suicide: a systematic review of the literature. [online] The Journal of Clinical Psychiatry, 75 (11), pp. 1242-53. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25470085 [accessed 1 Nov. 2017].
• In a different study, involving children aged 9, 11 or 13 years, depression predicted the subsequent level of C -reactive protein (CRP)
  • C -reactive protein is a marker of inflammation and is raised in infection or inflammation in the body Copeland, W. E., Shanahan, L., Worthman, C., Angold, A. and Costello, E. J. (2012). Cumulative depression episodes predict later C-reactive protein levels: a prospective analysis. [online] Biological Psychiatry, 71(1), pp. 15–21. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22047718 [accessed 1 Nov. 2017].
• Evidence shows inflammatory markers were higher in about a third of depressed patients compared to the majority of non-depressed subjects Raison, C. L. and Miller, A. H. (2011). Is depression an inflammatory disorder? [online] Current Psychiatry Reports, 13 (6), pp. 467–75. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21927805 [accessed 1 Nov. 2017].

• An experiment which involved injecting Lipopolysaccharides (LPS) into animal bodies led to severe learning deficits
• These deficits were accompanied by an increase in beta-amyloid plaque in their hippocampus, and beta-amyloid plaque is a marker for Alzheimer’s disease

Behaviour and mood are heavily influenced by neurotransmitters and brain networks.

Cytokines, both pro-inflammatory and anti-inflammatory cytokines, are small proteins released by cells which have a specific effect on the interactions and communications with cells. Zhang, J. M. and An, J. (2007). Cytokines, Inflammation and Pain. [online] International Anesthesiology Clinics, 45 (2), pp. 27-37. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2785020/ [accessed 2 Nov. 2017].

Cytokines have been shown to interact with virtually every physiological process relevant to depression, including the processing and function of neurotransmitters.

• In research, administering cytokines profoundly affected the production, uptake and release of key neurotransmitters for mood and behaviour, serotonin, noradrenaline and dopamine Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].

Increased cytokines levels were shown to lead to:

• Reduced serotonin levels (the neurotransmitter which regulates our moods, appetite and sleep)
  • Indeed cytokines are involved in the breakdown of serotonin
• Decreased dopamine uptake (the pleasure and reward neurotransmitter)
• Reduced GABA levels (the calming and focus neurotransmitter)
• Reduced levels of acetylcholine (the neurotransmitter involved in memory and stress) Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].

There seems to be a symbiotic relationship between inflammation and stress hormones in that inflammatory cytokines can trigger the release of stress hormones; and conversely, elevated stress hormones can trigger inflammation.

Meanwhile, there is a correlation between high levels of stress hormones, inflammation and depression:

• The administration of inflammatory cytokines acutely impact the HPA axis, which is activated during the stress response Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
• Cytokines stimulate the release of hormones involved in the stress response such as corticotropin-releasing hormone (CRH),  adrenocorticotropic hormone (ACTH) and cortisol
• All these stress hormones are increased in patients with depression Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].
• Conversely, impairment in the HPA axis activity due to chronic stress and the associated rise in cortisol can cause enhanced susceptibility to inflammation Silverman, M. N. and Sternberg, E. M. (2012). Glucocorticoid regulation of inflammation and its functional correlates: from HPA axis to glucocorticoid receptor dysfunction. [online] Annals of the New York Academy of Sciences, 1261(1), pp. 55–63. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22823394 [accessed 1 Nov. 2017].
• Chronic stress causes the activation of the HPA axis, and of inflammtory cytokines which can lead to suppressed immunity Tian, R., Hou, G., Li, D. and Yuan, T.-F. (2014). A possible change process of inflammatory cytokines in the prolonged chronic stress and its ultimate implications for health. [online] The Scientific World Journal. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24995360 [accessed 1 Nov. 2017].

Autoimmune disease occurs when the body’s immune system attacks the body’s own cells and tissues. Therefore it involves an inflammatory response.

Types of autoimmune disease include:

• Rheumtaoid arthritis
• Systemic lupus erythematosus (SLE)
• Multiple sclerosis (MS)
• Psoriasis
• Crohn’s disease
• Hashimoto’s thyroiditis

The cause of autoimmune disease in many cases is unknown. There are many factors implicated:

• Autoimmune conditions are more common in females suggesting a hormonal component
• They can run in families, suggesting a genetic component
• There is a theory that they are caused by gut issues such as leaky gut or gluten intolerance

Kharrazian, D. (2013). Why Isn’t My Brain Working? Carlsbad, CA: Elephant Press, p. 459. https://www.ncbi.nlm.nih.gov/pubmed/26343710

There is a correlation between autoimmune disease and mental health issues:

• Autoimmune disease and severe infections are risk factors for schizophrenia and other mental illness Benros, M. E., Eaton, W. W., & Mortensen, P. B. (2014). The epidemiologic evidence linking autoimmune diseases and psychosis. Biological Psychiatry, 75 (4), pp. 300–6. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24199668 [accessed 1 Nov. 2017].
• A range of psychiatric disorders including psychosis has been observed to occur more frequently alongside autoimmune diseases
• In some studies, a prior autoimmune disease increased the risk of depression by 45% Benros, M. E., Waltoft, B. L., Nordentoft, M., Krogh, J. and Mortensen, P. B. (2012). Autoimmunity and infections as risk factors for depression and other severe mental illnesses. [online] Neurology, Psychiatry and Brain Research, 18 (2), pp. 40–1. Available at: http://www.sciencedirect.com/science/article/pii/S0941950012000152 [accessed 1 Nov. 2017].

Brain-reactive antibodies (antibodies which only affect brain tissue) and inflammation are the key factors implicated in the link between autoimmunity and mental health problems.

Brain-reactive antibodies are present in about 2-3% of the population and normally cause no harm.

Brain-reactive antibodies have been implicated in:

• Autism
• Obsessive-compulsive disorder
• Schizophrenia

These conditions are believed to originate during pregnancy in the developing foetus:

• Elevated levels of antibodies have been found at the end of pregnancy in mothers of children who later develop schizophrenia
• Elevated brain-reactive antibodies have been found in pregnant mothers and their children who later develop autism Benros, M. E., Waltoft, B. L., Nordentoft, M., Krogh, J. and Mortensen, P. B. (2012). Autoimmunity and infections as risk factors for depression and other severe mental illnesses. [online] Neurology, Psychiatry and Brain Research, 18 (2), pp. 40–1. Available at: http://www.sciencedirect.com/science/article/pii/S0941950012000152 [accessed 1 Nov. 2017].

In response to infection and/or inflammation, the release of inflammatory cytokines stops the development of new nerve cells in the brain known as “neurogenesis” or “neuroplasticity”.

Evidence indeed shows that infection and inflammation, which activate the release of cytokines, affect behaviour and cognitive functions such as memory.Miller, A. H., Maletic, V. and Raison, C. L. (2009). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression. [online] Biological Psychiatry, 65(9), pp. 732–741. Available at: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01532-1/fulltext [accessed 1 Nov. 2017].

Just as inflammation and inflammatory cytokines can reduce neurogenesis, inflammation is also implicated in neurodegenerative diseases such as Alzheimer’s disease.

The chemical markers associated with inflammation are consistently raised in Alzheimer’s and can be used to predict cognitive decline and the development of dementia.Najjar, S., Pearlman, D. M., Alper, K., Najjar, A. and Devinsky, O. (2013). Neuroinflammation and psychiatric illness. Journal of Neuroinflammation, 10 (1), p. 43. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23547920 [accessed 1 Nov. 2017].

During any physical illness, the immune system communicates with the brain through the secretion of cytokines.Yirmiya, R. (2000). Depression in medical illness: the role of the immune system. [online] The Western Journal of Medicine, 173 (5), pp. 333–6. Available at: https://www.ncbi.nlm.nih.gov/pubmed/11069873 [accessed 1 Nov. 2017].

Due to the interaction between the immune system and the brain, non-neurological infections such as pneumonia and urinary tract infection (UTI) can be accompanied by acute syndromes of brain dysfunction Han, J. H. and Wilber, S. T. (2013). Altered Mental Status in Older Emergency Department Patients. [online] Clinics in Geriatric Medicine, 29 (1), pp. 101–36. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614410/ [accessed 1 Nov. 2017] characterised by delirium and confusion. Inouye, S. K., Bogardus, S. T. Jr., Charpentier, P. A., Leo-Summers, L., Acampora, D., Holford, T. R. and Cooney, L. M. Jr. (1999). A multicomponent intervention to prevent delirium in hospitalized older patients. [online] The New England Journal of Medicine, 340 (9), pp. 669-76. Available at: https://www.ncbi.nlm.nih.gov/pubmed/10053175 [accessed 1 Nov. 2017].

Benros, M. E., Eaton, W. W., & Mortensen, P. B. (2014). The epidemiologic evidence linking autoimmune diseases and psychosis. Biological Psychiatry, 75 (4), pp. 300–6. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24199668 [accessed 1 Nov. 2017].

There is strong evidence associating infectious agents with mental health issues.

Infectious agents include:

• Bacteria
• Viruses
• Parasites
• Fungi
• Prions

These infectious agents can cause mental health issues, including cognitive, psychotic and mood disorders.

Viruses and bacteria

Viruses and bacteria can act as endocrine disruptors, disturbing hormonal balance. They can also create an inflammatory-immune response.

• Epstein barr Gottfried, S. (2013). The Hormone Cure. New York: Scribner, p. 285.
• Cytomegalovirus

Prenatal infections in the mother are increasingly recognized as playing a role in the development of various brain disorders in the offspring such as:

• Depression
  • A prior history of hospitalization with infection increased the risk of depression by 62% Benros, M. E., Eaton, W. W., & Mortensen, P. B. (2014). The epidemiologic evidence linking autoimmune diseases and psychosis. Biological Psychiatry, 75 (4), pp. 300–6. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24199668 [accessed 1 Nov. 2017].
• Schizophrenia
• Autism
• Bipolar disorder
• Mental retardation
• Cerebral palsy

HIV has been associated with a large number of psychiatric illnesses from depression to substance abuse.

Impaired cognition has been associated with several infections including:

• Herpes
  • Herpes simplex virus type 1 (HSV-1) causes cold sores, eye infection and encephalitis
  • Exposure to HSV-1 has been associated with cognitive impairment (memory tests) as well as emotion processing in otherwise healthy individuals
• Hepatitis
• HIV

Patients affected with sepsis (sepsis occurs when infectious agents (or toxins) enter the bloodstream and tissue and can cause serious organ damage and ultimately death if not treated) and encephalitis have been shown to have cognition issues long after the infection has cleared.

Schizophrenia is highly disabling, and so far the following infectious agents have been implicated as potential causes:

• Herpes type 2
• Borna virus
• Chlamydia infections
• Toxoplasmosis
  • Toxoplasmosis is a parasitic disease caused by ingesting food or drink contaminated with parasites shed from cats
  • Toxoplasmosis infection has been associated with a wide range of psychiatric disorders including schizophrenia, personality disorders and obsessive compulsive disorders

Fungal infections and mental health

Candida albicans is a fungal infection.

• Candida albicans is a new candidate for studies in connection with mental health
• Candida albicans has been associated with reduced cognitive function and potentially schizophrenia

Parasites and mental health

• All parasites emit toxins known as the indole catabolites. These burden the liver and kidneys and can make you become fatigued, irritable and can cause weight gain.
• Parasites are known to be connected to immune dysfunction, chronic fatigue, sleep disturbances, teeth grinding, IBS, anemia, joint aches and pains, skin conditions and constipation
• Parasites affect everyone differently. One person can be affected by parasites and not have mood problems and another person may get depressed or have digestive problems
• The parasite toxoplasma (which causes toxoplasmosis) is known to be correlated with generalised anxiety disorder twice as frequently as other parasites
• A study in 2006 showed that women with high levels of toxoplasma were more likely to give birth to children who later became schizophrenic and had birth defects Scott, T. and Gittleman, L. (May 2015). The Parasite/Anxiety Connection. [online] The Anxiety Summit, Season 3. Available at: http://season3.theanxietysummit.com/ [accessed 1 Nov. 2017]. 

• Sugars and refined carbohydrates Kharrazian, D. (2013). Why Isn’t My Brain Working? Carlsbad, CA: Elephant Press, p. 459.
• Processed and fried foods which are high in salt, sugar and bad fats (trans fats and hydrogenated fats)
• Nutritional deficiencies Hyman, M. (2008). The UltraMind Solution. New York: Scribner, pp. 171-94.
• Alcohol Kharrazian, D. (2013). Why Isn’t My Brain Working? Carlsbad, CA: Elephant Press, p. 459.

• Often caused by food allergens such as gluten Kharrazian, D. (2013). Why Isn’t My Brain Working? Carlsbad, CA: Elephant Press, p. 459.
• Food allergies can be a major cause of brain inflammation Hyman, M. (2008). The UltraMind Solution. New York: Scribner, pp. 171-94.

Fewer than seven hours a night.Hyman, M. (2008). The UltraMind Solution. New York: Scribner, p. 185.

Lack of oxygen which could be due to:

• Poor breathing habits
• Insufficient exercise
• Urban living and pollution
• Superficial breathing due to chronic stress
• Poor circulation
• Iron deficiency

Sedentary behaviour may contribute to negative mood by enhancing the inflammatory signaling pathway and increasing mood disturbance.Endrighi, R., Steptoe, A. and Hamer, M. (2015). The effect of experimentally induced sedentariness on mood and psychobiological responses to mental stress. The British Journal of Psychiatry. Available at: http://bjp.rcpsych.org/content/208/3/245 [accessed 1 Nov. 2017].

Excessive exercise or exercise which is too intense may lead to an excess release of stress hormones, physical damage, free radical damage and inflammation. This in turn may contribute to the development of mental health disorders.

• Gut dysbiosis and Leaky gut (which allows inflammatory substances such as Lipopolysaccharides (LPS) to pass through the gut barrier into the bloodstream, contributing to inflammation)
• Poor digestion Hyman, M. (2008). The UltraMind Solution. New York: Scribner, pp. 171-94.
• Use of medicines such as antibiotics, NSAIDs (non-steroidal anti inflammatory drugs), proton pump inhibitors Minocha, A. (2014). Is It Leaky Gut or Leaky Gut Syndrome? Shreveport, LA: Logos Enterprises LLC.

Toxins such as mercury and pesticides, are neurotoxins which can cause inflammation in the brain. Hyman, M. (2008). The UltraMind Solution. New York: Scribner. pp. 171-194

Toxicity and then inflammation can also be triggered by certain pharmaceutical and recreational drugs such as alcohol, antibiotics, contraceptive pills, etc.

Low grade, hidden or chronic infections Hyman, M. (2008). The UltraMind Solution. New York: Scribner. pp. 171-194

Stress, whether acute or chronic, can cause an inflammatory reaction in the body and the brain. Hyman, M. (2008). The UltraMind Solution. New York: Scribner. pp. 171-194

Trauma, whether physical or psychological, can lead to inflammation.

Chronic childhood trauma such as abuse will tend to cause mental health issues, not just for psychological reasons, but also for biochemical ones — the stress to the system involved in chronic trauma can lead to inflammation, which in turn can lead to mental health issues.