RELEVANCE BETWEEN AGE OF ONSET AND HOSPITALIZATION CHARACTERISTICS OF MAJOR DEPRESSIVE DISORDERS: A 16 YEARS RETROSPECTIVE COHORT STUDY

Abstract Background Age of onset influences the progression of many diseases and even serves as a potential driver. But in Major Depressive Disorder, there are no uniform findings on the effect of age of onset on the course of the disease. Objectives We thus retrospectively investigated a large-scale cohort to explore the effect of age of onset on the course of Major Depressive Disorders. Method In this study, a total of 38,671 inpatients were surveyed over 16 years, and 6,773 inpatients were eventually included in the statistical analysis after applying rigorous data criteria. We used logistic regression models to calculate the odds ratio for the risk of relapse. Results In the subset of 4884 participants with first hospitalization, the first episode of depressive disorder was concentrated in middle age (39.5%). The differences in the length of stay in the different age of onset groups were statistically significant (F=56.852, df1=3, df2=4880, P<0.001, ω2=0.033), and the Bonferroni post hoc test suggested a longer length of stay in the adolescent onset group. Similarly, this difference was also observed in the subset of 1229 participants with relapse hospitalization(F=5.985, df1=3, df2=1225, P<0.001, ω2=0.012). The proportion of patients in the adolescent-onset group with 2 or more relapse hospitalizations within 1 year was found to be higher than that without relapse (6.7%Vs 2.7%, X2=12.685, df=6, P <0.001). Logistic regression suggests that patients with adolescent onset are at higher risk for 2 or more relapses within one year (B=0.881, OR=2.41, 95%CI 1.37-4.23, P=0.002). Conclusions This is the first large sample size study to examine age at onset and risk of relapse at the individual level in a Chinese population. Our study found that adolescent onset is more likely to lead to chronicity of MDD. These findings will contribute to more precise disease typing in MDD, as well as customized individualized prevention and treatment programs.