Background Children and adolescents are in the critical period of individual mental health development. In the face of public health emergencies, children and adolescents have weak psychological coping ability and are prone to various psychological problems. Objective To understand the changing trend of the disease composition ratio of children and adolescents inpatients in mental health centers of general hospitals under public health emergencies, so as to provide references for future research and intervention practices on adolescent mental health during similar major public health emergencies. Methods From January 1, 2018 to December 31, 2022, the main diagnosis of hospitalization and discharge in the Mental Health Center of West China Hospital, Sichuan University met any of the diagnostic criteria of the International Classification of Diseases, tenth edition (ICD-10), including schizophrenia, schizotype disorder and delusional disorder, depressive disorder, bipolar disorder, anxiety disorder, and post-traumatic stress disorder. A total of 6 613 children and adolescents were included in the study. The age, sex, ethnicity, residence, length of stay and other information of inpatients were collected retrospectively. The trend χ2 test was used to examine the change trend of disease composition ratio. Results There were significant differences in age, length of stay, sex and payment method between children and adolescents before and during the pandemic (t=10.743, 4.082, χ2=29.092, P<0.01). During the COVID-19 pandemic, the proportions of depressive disorder, bipolar disorder and anxiety disorder in hospitalized children and adolescents showed an increasing trend (χ2trend=11.058, 67.333, 17.276, P<0.01). The proportions of schizophrenia, schizotype disorder and delusional disorder showed a decreasing trend (χ2trend=219.924, P<0.01). The proportion of bipolar disorder in hospitalized patients aged 0-14 years showed an increasing trend (χ2trend=18.207, P<0.01). The proportion of bipolar disorder and anxiety disorder in hospitalized patients aged 15 to 19 years was increasing (χ2trend=57.339, 19.011, P<0.01). The proportion of depressive disorder and bipolar disorder in male students increased (χ2trend==21.729, 11.380, P<0.01). The proportion of bipolar disorder and anxiety disorder in girls showed an increasing trend (χ2trend=54.830, 14.377, P<0.01). Conclusion Compared with the pre-pandemic period, during the pandemic period, the inpatients of children and adolescents in mental health centers of general hospitals were mainly girls, with younger age and shorter hospitalization duration, and the proportion of children and adolescents with depressive disorder, bipolar disorder and anxiety disorder showed an increasing trend. |