To analyze the influencing factors on the occurrence of anxiety and depression among secondary school students in Shanxi Province in 2023 based on the random forest algorithm and to construct a prediction model to provide a scientific basis for preventing and controlling the occurrence of negative emotions such as anxiety and depression among secondary school students.

In September 2023, 104 826 secondary school students in 11 cities of Shanxi Province were selected by stratified random whole-cluster sampling method for questionnaire survey, and the Generalized Anxiety Scale (GAD-7) and the Center for Streamlined Depression Scale (CES-D) were used to investigate anxiety and depression. Epidata was used for database establishment, chi-square test was used for between-group comparisons, logistic regression was used for influencing factor analysis, and Python 3.7 was used to establish a random forest prediction model and rank the importance of each variable.

The detection rates of anxiety and depression among secondary school students in Shanxi Province in 2023 were 33.26% and 23.72%, respectively, and were higher for girls than for boys, and higher for students in general and vocational high schools than for junior high school students. The results of multifactorial regression analysis showed that female students(OR: 1.846、1.655，95% CI: 1.794-1.901、1.602-1.710), high school(OR: 2.019、1.670，95% CI: 1.956-2.083、1.612-1.731), vocational high school(OR: 1.167、1.356，95% CI: 1.085-1.254、1.254-1.466), non-conventional family(OR: 1.105、1.248，95% CI: 1.072-1.140、1.206-1.292), living in school(OR: 1.102、1.117，95% CI: 1.070-1.136、1.080-1.155), eating fried food ≥1 time/day(OR: 1.296、1.375，95% CI: 1.227-1.369、1.297-1.457), being seriously injured(OR: 1.636、1.688，95% CI: 1.524-1.755、1.569-1.816), being bullied in school(OR: 2.315、3.411，95% CI: 2.150-2.492、3.165-3.677), being scolded by parents(OR: 2.881、3.191，95% CI: 2.766-3.001、3.059-3.328), smoking(OR: 1.344、1.435，95% CI: 1.266-1.427、1.349-1.527), drinking alcohol(OR: 2.062、2.113，95% CI: 1.978-2.151、2.022-2.208), and Internet addiction(OR: 3.635、3.976，95% CI: 3.289-4.016、3.611-4.377) were the risk factors for the detection of anxiety and depressive mood in secondary school students, and eating fresh fruits≥1 time/day(OR: 0.824、0.758，95% CI: 0.800-0.849、0.73-0.783), eating breakfast frequently(sometimes: OR: 0.843、0.715，95% CI: 0.781-0.910、0.661-0.773; daily: OR: 0.538、0.384，95% CI: 0.500-0.579、0.356-0.414), doing moderate to high-intensity exercise frequently(1-3 days/week: OR: 0.888、0.821，95% CI: 0.854-0.923、0.787-0.857; ≥4 days/week: OR: 0.931、0.848，95% CI: 0.893-0.971、0.810-0.887), and having a large number of physical education hours(2-3 sessions/week: OR: 0.826、0.859，95% CI: 0.801-0.853、0.829-0.890; ≥4 sessions/week: OR: 0.741、0.758，95% CI: 0.695-0.789、0.705-0.815) were the protective factors for the detection of anxiety and depressive protective factors for mood detection. Drinking sugary drinks≥1 time/day(OR: 1.198，95% CI: 1.122-1.279) and eating vegetables≥1 time/day(OR: 0.861，95% CI: 0.828-0.895) were independent risk factors and independent protective factors for the detection of depressed mood, respectively. The AUC of the Random Forest model predicting the risk of anxiety and depressed mood was 0.999 8 and 0.999 7, with a sensitivity of 99.53% and 99.67%, and a specificity of 99.47% and 98.98%, respectively. Being scolded by parents, Internet addiction and alcohol consumption were the common factors that had a greater degree of influence on anxiety and depression among secondary school students.

The detection rate of anxiety and depression among secondary school students in Shanxi Province is high, being scolded by parents, alcohol consumption and Internet addiction are the factors that have a greater influence on the occurrence of anxiety and depression, and the random forest model has a high predictive value.