The Link Between the Immune System, Environment, and Psychosis

Area of Science:

• Neuroscience
• Immunology
• Psychiatry

Background:

• Growing interest in the relationship between psychosis spectrum disorders (PSD) and immune system alterations.
• Evidence suggests increased peripheral inflammation in PSD, but the link to central brain inflammation remains unclear.
• Methodological factors like medication and lifestyle confound inflammation studies in PSD.

Purpose of the Study:

• To investigate the correlation between peripheral inflammation and central inflammation in the brain for PSD.
• To explore inflammation-mediated pathways as a potential final-common pathway for environmental risk factors in PSD.
• To propose an integrative framework and future research directions for understanding immune dysfunction in PSD.

Main Methods:

• Review of epidemiological and clinical studies on inflammation markers in PSD.
• Analysis of clinical and animal studies on inflammatory processes in neuropsychiatric domains.
• Speculative framework integrating environmental risks and neuroinflammation in PSD.

Main Results:

• Peripheral inflammation markers are elevated in PSD, but central correlates are uncertain.
• Inflammatory processes may underlie trans-diagnostic neuropsychiatric features (e.g., positive/negative valence, affect, cognition).
• Inflammation may act as a final-common pathway for environmental risks like adversity, cannabis use, and social exclusion.

Conclusions:

• Inflammation is implicated in PSD pathophysiology, potentially linking environmental factors to brain changes.
• Further research is needed to disentangle the complex interplay between immune dysfunction and PSD.
• An integrative framework is proposed to guide future investigations into neuroinflammation and psychosis.