TY  - JOUR
A1  - Misiak, Błażej
A1  - Wójta-Kempa, Monika
A1  - Samochowiec, Jerzy
A1  - Schiweck, Carmen
A1  - Aichholzer, Mareike
A1  - Reif, Andreas
A1  - Samochowiec, Agnieszka
A1  - Stańczykiewicz, Bartłomiej
T1  - Peripheral blood inflammatory markers in patients with attention deficit/hyperactivity disorder (ADHD): a systematic review and meta-analysis
T2  - Progress in neuro-psychopharmacology and biological psychiatry
N2  - Highligths
• Immune-inflammatory alterations might appear in subjects with ADHD.
• Blood levels of tumor necrosis factor-α might be reduced in individuals with ADHD.
• Individuals with ADHD might show elevated blood levels of interleukin-6.
Abstract
It has been observed that subclinical inflammation might be involved in the pathophysiology of attention deficit/hyperactivity disorder (ADHD). However, studies investigating peripheral blood levels of immune-inflammatory markers have provided mixed findings. We performed a systematic review and meta-analysis of studies comparing unstimulated serum or plasma levels of C-reactive protein (CRP) and cytokines in subjects with ADHD and healthy controls (the PROSPERO registration number: CRD 42021276869). Online searches covered the publication period until 30th Sep 2021 and random-effects meta-analyses were carried out. Out of 1844 publication records identified, 10 studies were included. The levels of interleukin (IL)-6 were significantly higher in studies of participants up to the age of 18 years (k = 10, g = 0.70, 95%CI: 0.10–1.30, p = 0.023) and after including those above the age of 18 years (k = 10, g = 0.71, 95%CI: 0.12–1.31, p = 0.019). In turn, the levels of tumor necrosis factor-α (TNF-α) were significantly lower in subjects with ADHD compared to healthy controls (k = 7, g = −0.16, 95%CI: −0.30 - -0.03, p = 0.020). Individual studies had a high contribution to the overall effect, since the overall effect was no longer significant after removing single studies. No significant differences were found with respect to the levels of CRP, IL-1β, IL-10 and interferon-γ. The present findings indicate that individuals with ADHD tend to show elevated levels of IL-6 and reduced levels of TNF-α. Larger and longitudinal studies recording potential confounding factors and comorbid psychopathology are needed to confirm our findings.
KW  - ADHD
KW  - Inflammation
KW  - Immunity
KW  - Biomarker
KW  - Neurodevelopmental disorder
KW  - Mental disorder
Y1  - 2022
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/78541
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-785416
SN  - 0278-5846
VL  - 118
IS  - 110581
PB  - Elsevier
CY  - Amsterdam
ER  -