Depression is one of the most common mental health problems among people living with HIV (PLHIV) (Niu et al., 2016; Rezaei et al., 2019). A meta-analysis showed that the prevalence of depression among PLHIV worldwide was 31 % (28 %-34 %) (Rezaei et al., 2019). Another meta-analysis estimated that >50 % of PLHIV in China suffered from depression or experience symptoms of depression (Wang et al., 2018). Depression, as one of the important factors affecting the health-related quality of life (HRQoL) (Niu et al., 2016), is also associated with antiretroviral treatment failure, accelerated disease progression, and adverse changes in the immune or endocrine systems of PLHIV, which may increase the risk of death for patients (Rivera-Rivera et al., 2016; Kong et al., 2012; Castilho et al., 2020). Understanding the factors associated with depressive symptoms is one of the keys to ensuring a good HRQoL among PLHIV, which has been proposed as the fourth target to end AIDS, following the 95-95-95 targets (UNAIDS, 2021; Andersson et al., 2020).

The onset of depression is thought to be the result of a combination of individual physiological, psychological, and social factors, which may change over time (Clark et al., 2018; Garrido-Hernansaiz and Alonso-Tapia, 2017). For newly diagnosed PLHIV, the HIV diagnosis can be an immediate stressor leading to depression (Liu et al., 2017; Tao et al., 2017), and subsequent psychological changes are common, especially in the first year after HIV diagnosis (Li et al., 2023). However, there is limited research on the longitudinal changes in depression among newly diagnosed PLHIV in China (Li et al., 2023; Niu et al., 2019). Although the overall depression of the newly diagnosed PLHIV had been alleviated, the changes in depression varied in different patterns, with some participants being persistently depressed, some relieved, and some worsening (Li et al., 2023; Niu et al., 2019). Understanding the different changes of depression among newly diagnosed PLHIV can inform the efficient mental health resources allocation to improve their mental health.

According to the network theory of mental disorders, the cause of the development and maintenance of mental illness is the causal interaction between its symptoms; if this relationship is strong enough, it will lead to a feedback loop that enables the illness to persist (Borsboom, 2017). However, traditional theories of psychopathology have used total scores on standard scales to indicate the severity of mental symptoms, overlooking the important distinctions between different symptoms and their interactions (Beard et al., 2016; Fried and Nesse, 2015). Network analysis is a new method capable of mapping interactions of particular symptoms both within and between them, with nodes representing symptoms and edges representing associations between pairs of nodes (Epskamp et al., 2018; Burger et al., 2023). Network analysis can also help to identify the most influential nodes within a symptom network and isolate potentially useful targets for prevention and intervention (Robinaugh et al., 2016). It has been widely used to explore the interrelations between mental health symptoms in different populations through cross-sectional or longitudinal designs, revealing variations in nodes and edges across different populations (Zhang et al., 2023; Sun et al., 2024). However, there have been limited network analysis studies conducted to explore mental health symptoms among PLHIV, including exploring the interrelationships between mental health symptoms (depression and anxiety) and cognitive impairment (Ma et al., 2024), exploring the relationship between anxiety, depression, and sleep disturbance (Wang et al., 2021), and examining the effects of HIV stigma processes on self-concept and depressive symptoms (Norcini Pala and Turan, 2024), etc. The interactions between individual depressive symptoms among PLHIV remained unexplored within longitudinal study designs.

Therefore, we conducted this cohort study to understand the factors associated with depressive symptoms among newly reported PLHIV in Guangdong Province, China. In addition, the interactions between individual depressive symptoms at baseline and follow-up were explored to identify targets for prevention and intervention. Finally, the impacts of different changes in depressive symptoms on the risk of mortality were further explored.