Brick by Brick: Building a Transdiagnostic Understanding of Inflammation in Psychiatry

Abstract

Inflammatory phenomena are found in many psychiatric disorders-notably, depression, schizophrenia, and posttraumatic stress disorder. Inflammation has been linked to severity and treatment resistance, and may both contribute to, and result from, the pathophysiology of some psychiatric illnesses. Emerging research suggests that inflammation may contribute to symptom domains of reward, motor processing, and threat reactivity across different psychiatric diagnoses. Reward-processing deficits contribute to motivational impairments in depression and schizophrenia, and motorprocessing deficits contribute to psychomotor slowing in both depression and schizophrenia. A number of experimental models and clinical trials suggest that inflammation produces deficits in reward and motor processing through common pathways connecting the cortex and the striatum, which includes the nucleus accumbens, caudate nucleus, and putamen. The observed effects of inflammation on psychiatric disorders may cut across traditional conceptualizations of psychiatric diagnoses. Further study may lead to targeted immunomodulating treatments that address difficult-to-treat symptoms in a number of psychiatric disorders. In this review, we use a Research Domain Criteria framework to discuss proposed mechanisms for inflammation and its effects on the domains of reward processing, psychomotor slowing, and threat reactivity. We also discuss data that support contributing roles of metabolic dysregulation and sex differences on the behavioral outcomes of inflammation. Finally, we discuss ways that future studies can help disentangle this complex topic to yield fruitful results that will help advance the field of psychoneuroimmunology.

More than Addiction—The Nucleus Accumbens Contribution to Development of Mental Disorders and Neurodegenerative Diseases

“…Recent studied have shown that in many mental diseases, including schizophrenia, an inflammatory process develops in NAc, and this is associated with abnormal DA concentration in this brain area [ 88 , 89 ]. This can result in neuronal atrophy and changes in the axo-dendritic system, leading to the exacerbation of disease symptoms.…”

Role of Neuroglia in the Habenular Connection Hub of the Dorsal Diencephalic Conduction System

“…Something that is fairly odd is that so little attention has been paid to the possible role of cytokines in causing astroglial-induced changes in the function of the DDCS. After all, astrocytes are known to be of great significance in all sorts of processes that cause severe neuroinflammation [61][62][63][64][65], and so why would this not play a role in the lighter forms that are obvious in mental disorders [7,10,21]? Although microglia may be considered the dominant immunocompetent cells of the CNS, astrocytes participate fully in inducing and mediating the neuroinflammatory responses.…”

“…[4] on the influence of grief on the function of B and T cells and hormone levels in the spouses of deceased patients initiated what would later develop into psychoneuroimmunology [5][6][7]. Currently, the connection between the functioning of the immune system and the development of mental disorders is widely accepted [8][9][10][11]. This is especially well conceived for depression [12][13][14][15], schizophrenia [16][17][18] and posttraumatic stress disorder [19][20][21].…”

Collaboration between Psychiatrists and Other Allied Medical Specialists for the Treatment of Delusional Disorders

“…Inflammatory phenomena are considered part of the pathophysiology of both chronic gastrointestinal disorders and chronic psychoses [ 72 , 73 ]. The interplay between gastrointestinal symptoms and mental health disorders has been widely discussed in relation to several disorders [ 72 ].…”