Increased interleukin 18 activity in adolescents with early-onset psychosis is associated with cortisol and depressive symptoms.
Psychoneuroendocrinology 2020;
112:104513. [PMID:
31761332 DOI:
10.1016/j.psyneuen.2019.104513]
[Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/14/2019] [Accepted: 11/12/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE
Evidence indicates that the pathophysiology of adult psychosis involves immune dysregulation, but its associations with stress are often not considered. The inflammatory cytokine interleukin (IL)-18, which is elevated in adult schizophrenia, is suggested to be sensitive to stress. We compared the associations of IL-18 with cortisol and clinical variables in adolescents with early-onset psychosis (EOP) aged 12-18 years and age-matched healthy controls (HC).
METHOD
We measured serum IL-18, IL-18 binding protein (IL-18BP), IL-18 receptor accessory protein (IL-18RAP), IL-18 receptor 1 (IL-18R1) and cortisol, and calculated the IL-18/IL-18BP ratio in patients (n = 31) and HC (n = 60). Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale and depressive symptoms by the Mood and Feelings Questionnaire-Child version (MFQ-C). Bivariate correlation analysis was used to explore relationships between IL-18/IL-18BP ratio and cortisol, depression and other clinical characteristics. Hierarchical multiple linear regression analysis was used to assess their individual contributions to the variance of the IL-18/IL-18BP ratio.
RESULTS
Patients had significantly higher IL-18 levels and IL-18/IL-18BP ratios than HC, but similar IL-18BP, IL-18RAP and IL-18R1. Both cortisol (R2 change = 0.05) and the MFQ-C score (R2 change = 0.09) contributed significantly to the variance in IL-18/IL-18BP ratios after controlling for confounders.
CONCLUSION
We found increased IL-18 system activity in adolescents with EOP. Cortisol and depressive symptoms each contributed to the variance in the IL-18/IL-18BP ratio. Our findings support activation of inflammatory pathways in adolescent psychosis and suggest interactions between stress, inflammation and depressive symptoms in EOP.
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