To explore the transition patterns of latent classes of depressive symptoms among postgraduate students and their influencing factors.

A prospective cohort study was conducted. Two waves of survey were carried out on 5 577 postgraduate students from an university in Hubei Province and another one in Anhui Province in October 2021 (T1) and October 2022 (T2). Self-Rating Depression Scale and College Students Mental Health Screening Scale were applied respectively to measure the severities of depressive symptoms and developmental distress. The optimal classification model was determined through the fitting indicators of the latent class model, mainly including indicators such as Entropy value, Lo-Mendell-Rubin (LMR), and Bootstrapped Likelihood Ratio Test (BLRT). Latent transition analysis was used to obtain the transition probabilities of latent class changes at different time points, and multivariate logistic regression analysis was employed to identify the factors influencing the latent class transition of depressive symptoms in the postgraduate students.

① The depressive symptoms could be classified into 3 categories among the postgraduate students (T1: Entropy=0.85, LMRP<0.05, BLRTP<0.001; T2: Entropy=0.88, LMRP<0.001, BLRT P<0.001), that is, a non-depressive symptom group (66.0% vs 64.3%), a mild depressive symptom group (25.6% vs 26.9%), and a moderate depressive symptom group (8.4% vs 8.8%). ② The probabilities of each latent class remaining in the original group at time point T2 were 84.1%, 56.9%, and 26.6%, respectively. The probability of transition from moderate to mild depressive symptom group was 41.3%, and the probability from mild to non-depressive symptom group was 29.3%.③ Adaptation challenges(OR=1.08, 95%CI: 1.02 to 1.16, P<0.05) and employment stress (OR=1.05, 95CI: 1.01 to 1.10, P<0.05) were promoting factors for the transition from non-depressive to mild depressive symptom group. Romantic troubles (OR=0.86, 95%CI: 0.76 to 0.99, P<0.05) was an obstructive factor for the transition from moderate to non-depressive symptom group.

There are 3 latent categories of depressive symptoms among postgraduate students. an obstructive factor for the transition from moderate to non-depressive symptom group.Adaptation challenges, employment stress and romantic troubles are important factors for the development of depressive symptoms.