Autoimmune Diseases and Psychotic Disorders

Abstract

The notion of immunological pathways playing a role in the etiology of a subset of psychotic disorders has received increased interest in the last decades. One of the findings that has spiked interest herein, is an apparent link between autoimmune diseases and psychotic disorders. This is supported by genetic findings associating immune-related genetic markers with schizophrenia and clinical studies finding increased levels of inflammatory markers in patients with psychosis. Several large-scale epidemiologic studies have found positive associations between autoimmune diseases and psychosis. Particularly, autoimmune diseases as multiple sclerosis and lupus are known to have higher frequencies of neuropsychiatric symptoms, including psychosis, compared to healthy controls. Cross sectional studies have found higher prevalence of psychiatric diagnoses among those with autoimmune diseases, and longitudinal studies have shown bidirectional associations between several autoimmune diseases and increased risks associated with schizophrenia. Moreover, a family history of autoimmune diseases has been shown to be associated with an increased risk of psychotic disorders and vice versa. In this review we will summarize the epidemiologic evidence on associations between autoimmune diseases and psychosis. Possible mechanisms accountable for the association will be discussed, amongst others the probable role of shared genetic risk factors, the impact of infections on both autoimmunity and the development of psychotic disorders, and the potential role of the microbiome. We discuss the findings on and influence of autoantibodies and dysregulation of T- and B-cells in both disease categories, and why further research hereon is needed. In addition to the potential importance of autoimmunity in etiological mechanisms of psychotic disorders, the association also brings important attention to somatic comorbidity in patients with psychotic disorders.

Expression and Functionality Study of 9 Toll-Like Receptors in 33 Drug-Naïve Non-Affective First Episode Psychosis Individuals: A 3-Month Study

“…In this sense, in this study we also found an altered functionality response in B cells, after 3 months of treatment. Altered B cell signaling might also increase the risk of autoimmunity [ 38 ], and as is known, autoimmunity is related to the etiology of schizophrenia [ 39 , 40 ].…”

Expression and functionality study of 9 Toll-like receptors in drug-naïve non-affective first episode psychosis individuals: a 3-month study

“…4a-4c). Altered B cell signaling may also increase the risk of autoimmunity (Rawlings et al, 2017), and as it is known, autoimmunity has been related with the etiology of schizophrenia (Benros et al, 2011;Jeppesen et al, 2019).…”

Book Review: I-Cubed and <i>The Autoimmune Brain</i>, A Five-Step Plan

“…Several large scale epidemiologic studies focusing on the relation between autoimmune disease and severe neuropsychiatric illnesses find a role for post-infections autoimmunity through I-Cubed with the production of pathogenic autoantibodies that have targets in brain areas such as the hippocampus, where psychiatric illness develops [7]. The hippocampus is highly dependent upon serotonergic neurotransmission and responsive to selective serotonin and norepinephrine reuptake inhibitors (SSRIs and SNRIs).…”