Borreliose-Gesellschaft e.V.


The Psychoimmunology of Tick Borne Diseases & its Association with Neuropsychiatric Symptoms

Robert Bransfield, MD, DLFAPA

Disease progression of neuropsychiatric symptoms in Lyme and associated diseases can be best understood by greater attention to psychoimmunology. Many contributors provoke and weaken the immune system; however persistent infections are invariably the major cause of pathological immune reactions. Immune mediated effects rather than direct microbial effects are more commonly the major contributor to the pathophysiological processes and disease progression. These immune effects include molecular mimicry with “autoimmune” reactions and persistent inflammation with cytokine effects and both of these mechanisms may be present at the same time in persistent infections. Sickness syndrome and interferon treatment are models to understand inflammatory cytokine effects upon mental and physical symptoms. Progressive inflammatory and other immune reactions have been proposed as a model to explain disease progression in depression, psychosis, dementia, autism and other mental illnesses. Pathophysiological mechanisms include inflammation driving oxidative stress, excitotoxicity, changes in homocysteine metabolism, indoleamine 2,3 dioxygenase mediated changes in serotonin metabolism and quinolinic acid.
Lyme disease has been associated with the proinflammatory cytokines IL-6, IL-8, IL-12, IL-18 and interferon γ, the chemokines CXCL12 and CXCL13 and increased levels proinflammatory lipoproteins. Borrelia burgdorferi surface glycolipids and flagella antibodies appear to elicit anti-neuronal antibodies. Other research has demonstrated anti-neuronal antibodies in chronic Lyme patients and Borrelia burgdorferi lipoproteins can disseminate from the periphery to inflame the brain. Autism spectrum disorders associated with Lyme and associated diseases may be mediated by a combination of inflammatory and autoimmune mechanisms.
In summary, attention to psychoimmunology is a major part of the future of psychiatry, persistent infections are major consideration in causing mental symptoms and many of the psychiatric symptoms associated with Lyme and associated diseases appear to be mediated by immune mechanisms. Therefore greater interaction is needed between infectious disease specialists, immunologists and mental health practitioners.