Psychopathological symptoms and their five-year change in a tracking cohort of Chinese firefighters: a multi-site observational study using the SCL-90

Introduction Firefighters in China are routinely exposed to physically and emotionally demanding situations, yet long-running tracking data on their mental-health profile are still scarce. Most published Chinese firefighter studies are cross-sectional, single-site, or limited to a particular incident. We took advantage of an annual occupational-health screening program to look at the Symptom Checklist-90 (SCL-90) profile of firefighters from two coastal cities, with the explicit goal of asking whether the symptom picture is stable across years and which factors drive it. Methods Annual SCL-90 records collected from 2021 and 2025 were pooled into a de-identified dataset. After deduplication and the removal of implausible age entries, 3,155 records from 1,911 unique firefighters remained. 805 firefighters had at least two assessments, forming a longitudinal subset. We computed standard Chinese screening criteria (total score ≥160, positive items ≥43, any subscale ≥2), compared subscale levels across gender, city and year, ran multivariable regressions, and used paired-sample t-tests and a linear mixed-effects model on the longitudinal subsample. Results Across the full sample, 15.2% of records were positive on the composite screening rule and 7.3% met the classical total-score threshold of 160. The most elevated subscale was Obsessive-Compulsive ( M = 1.38; 11.4% scoring ≥2), followed by Interpersonal Sensitivity, Depression and Hostility—a configuration that closely mirrors what previous studies of emergency personnel have reported. Total score declined steadily from 2021 ( M = 126.3) to 2025 ( M = 103.0), with a multivariable-adjusted year coefficient of −0.031 on the General Severity Index ( p < 0.001). Cross-city differences were small but consistent (Cohen’s d ≈ 0.15–0.24). Among the 805 longitudinally tracked firefighters, within-person scores tended to decrease modestly (mean Δtotal = −3.45, t (804) = 3.21, p = 0.001), with 32.9% improving, 46.2% staying stable and 20.9% worsening on a ±5-point criterion. Discussion Chinese firefighters in this five-year cohort show a psychopathological profile broadly comparable to that of firefighters in other settings, with obsessive-compulsive, interpersonal-sensitivity and hostility features standing out. The observed downward trend is encouraging but should be interpreted cautiously—sampling shifted from a small clinically-referred group in 2021 to a population-style screening by 2025. Roughly one in five tracked firefighters worsened over the observation window, which is the more actionable finding for occupational mental-health teams. Implications for early identification and stepped-care intervention are discussed.