Exploring the Role of Altered Serum IL‐12 and CRP Levels in the Pathophysiology and Development of Generalized Anxiety Disorder: A Cross‐Sectional Comparative Study

Cytokines and immune imbalance in generalized anxiety disorder (GAD) have attracted greater interest of all researchers. Studies indicate the involvement of pro-inflammatory cytokines in the pathogenesis of GAD. Therefore, the present study investigated the serum concentrations of interleukin (IL)-12 and carbon-reactive protein (CRP) in GAD patients to explore their role in the pathophysiology of diseases. This study included 52 GAD patients and 30 healthy controls (HCs) matched by age and sex. A psychiatrist diagnosed GAD patients and evaluated HCs according to the DSM-5 criteria. The severity of GAD cases was assessed using a standardized and validated clinical rating scale (GAD-7). ELISA kits were utilized to measure the serum concentrations of IL-12 and CRP in blood. GAD patients revealed significantly elevated concentrations of IL-12 (7.60 ± 1.53 pg/mL) than HCs (3.73 ± 0.42 pg/mL). These increased levels were positively correlated with GAD-7 scores (r = 0.377, p = 0.006). This IL-12 also demonstrated strong predictive ability in the receiver operating characteristic (ROC) investigation, with an area under the curve (AUC) of 0.828 (p < 0.001), indicating 81.6% sensitivity and 77.8% specificity at a threshold of 3.56 pg/mL. In contrast, the level of CRP was not changed between the groups (2.59 ± 0.13 vs. 2.55 ± 0.16 mg/L); furthermore, no association was detected between CRP levels and GAD-7 scores (r = 0.021, p = 0.881). Our investigation indicates that IL-12 in blood levels, but not CRP, may be associated with the pathophysiology and development of GAD. The altered serum IL-12 levels in GAD patients might be the result of disease pathogenesis. However, we recommend more advanced investigation with greater sample sizes to verify the probable diagnostic utility of IL-12.