Loneliness during the last phase of the COVID-19 pandemic in China: Trajectories, predictors, and impact on adolescent mental health

Background Little is known about the long-term courses of loneliness, associated risk factors and effect on mental health in adolescents during the COVID-19 pandemic. This study aimed to explore the trajectories of loneliness among Chinese adolescents during the last phase of the pandemic. We also aimed to identify risk factors in each loneliness course and the impact of loneliness on emotional problems, peer problems, hyperactivity and conduct problems. Methods We conducted longitudinal analyses using four waves of data from 2347 Chinese adolescents covering a period of 20 months (October 2021 – May 2023). Loneliness was assessed using the UCLA 3-Item Loneliness Scale. The self-reported version of the Strengths and Difficulties Questionnaire was utilized to evaluate participants’ mental health outcomes. Growth mixture modelling was employed to identify latent classes of loneliness trajectories. Associated risk factors were investigated using multinomial logistic regression model. Mixed-effects logistic regression models were constructed to examine the long-term impact of loneliness classes on mental health outcomes. Results Three courses of loneliness were identified: Decreasing Low Loneliness (58.71%), Increasing Medium Loneliness (36.52%), and Increasing High Loneliness (4.77%). Risk factors for poorer loneliness trajectories included lack of physical exercise habits, poorer mental health literacy, medium or low perceived social support, having study difficulties, being female, higher grades, and lower economic status. Loneliness courses were associated with the severity and variability of emotional problems, peer problems, hyperactivity and conduct problems. Individuals in the higher loneliness classes experienced a significant increase in these mental health problems over time. Conclusions During the last phase of the pandemic, a large proportion of adolescents in our study endured medium to high levels of loneliness with no signs of improvement. Both unfavorable loneliness trajectories adversely affected internalizing and externalizing problems and displayed an upward trend in these difficulties. Results highlight the importance of considering how to tackle loneliness both within the context of COVID-19 and more generally.