Peripheral immune system activity in young psychiatry patients

The interaction between the immune system and the central nervous system has been implicated in the development of psychiatric disorders in adult patients. However, comprehensive data regarding pediatric psychiatry are still lacking. This study aims to describe the distributions of various markers of immune system activity in a large clinical sample of children and adolescents and summarize the immunological profiles associated with different psychiatric disorders. We analyzed blood samples from 1543 patients aged 6-18 years (62 % female), admitted to the Child and Adolescent Psychiatry at the University Hospital of Tübingen between 2014 and 2024. Immune markers such as C-reactive protein and various cell counts and ratios were measured and regressed on psychiatric diagnoses according to the ICD-10 classification. Our findings revealed several distinct immunological profiles linked to specific psychiatric conditions in youth, such as higher CRP levels in patients with severe stress and adjustment disorders. The study underscores the potential role that immune system aberrations may play in mental health disorders and highlights the importance of investigating this link in this age group. However, some inconsistencies with the existing literature were found, such as the lack of association between depression and immune activity, which calls for further research to elucidate these relationships. Future studies should include longitudinal designs to better understand the causal pathways and potential for immune-targeted therapies in pediatric psychiatry.