Abstract： Objective:To explore the clinical manifestation and characteristics of not just right experiences (NJREs) in Chinese patients with obsessive-compulsive disorder (OCD), and the correlation with obsessive symptoms. The effect of clinical treatment on NJREs was studied.Methods:Clinical data were collected from 91 OCD patients in outpatient care at Beijing Anding Hospital, Capital Medical University, from March 2021 to March 2022. Patients were categorized into an untreated OCD group (40 cases, 24 males and 16 females, aged 29.3±8.1 years) and a treated OCD group (51 cases, 23 males and 28 females, aged 30.5±8.5 years) based on whether they received treatment in the month prior to admission. An age-matched healthy control group ( n=50, 25 males and 25 females, aged 30.8±8.9 years) was recruited simultaneously. The Not Just Right Experiences-Questionnaire-Revised (NJRE-Q-R) was used to evaluate the characteristics and severity of NJREs. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Yale-Brown Obsessive Compulsive Scale Symptoms Checklist (Y-BOCS-SC), Obsessive Belief Questionnaire (OBQ-44), Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) were used to evaluate the severity and types of obsessive-compulsive symptoms, obsessive-compulsive beliefs, anxiety, and depressive emotions. Analysis of variance was used to compare differences in NJREs among the untreated OCD group, treated OCD group and the healthy controls. Pearson correlation analysis was performed to explore the correlation between NJREs and clinical symptoms in OCD patients, and an intermediate effect model was used to analyze the mediation role of NJREs in the course of OCD. A treatment follow-up was conducted for 36 untreated OCD patients over 8 weeks, reassessing the severity of obsessive-compulsive symptoms and NJREs, as well as anxiety and depressive emotions to analyze the impact of treatment on NJREs. Results:The detection rates of NJREs in the untreated OCD group (87.5%) and the treated OCD group (96.8%) were higher than that those in the healthy control group (60%) with the difference statistically significant( χ 2=22.82, P<0.01). However, there was no statistically significant difference in the detection rate of NJREs between the untreated and treated OCD groups (χ 2=2.32, P=0.127). Regarding the severity of obsessive-compulsive symptoms and NJREs, the untreated and treated OCD groups showed statistically significant differences compared to the healthy control group (obsessive-compulsive symptom severity: 21.6±7.2 vs 20.9±7.1 vs 0.24±0.65; NJRE severity: 27.9±12.9 vs 27.7±11.8 vs 11.9±5.5; F=214.14, 37.05, both P<0.01). NJREs severity was positively correlated with the severity of obsessive-compulsive symptoms( r=0.522, P<0.05). Further mediation analysis revealed that NJRE severity significantly positively influenced Y-BOCS, BAI and BDI( β=0.398, 0.371, 0.312, all P<0.01); BDI significantly positively affected Y-BOCS( β=0.313, P<0.01); BAI had no significant impact on Y-BOCS ( β=0.071, P>0.01). After treatment, the severity of NJREs and obsessive-compulsive symptoms significantly reduced compared to the pre-treatment levels ( t=4.87, 2.01, both P<0.05). Changes in Y-BOCS total score were correlated with changes in NJRE-Q-R total score and NJRE-Q-R severity scores ( r=0.727, 0.555, both P<0.001). Conclusion:The detection rate and severity of NJREs in OCD patients are significantly higher than those in healthy controls. NJREs are correlated with obsessive-compulsive symptoms and NJREs can directly induce the development of obsessive-compulsive symptoms. Depressive emotions have a certain positive impact on the relationship between NJREs and obsessive-compulsive symptoms.