Occupational burnout, recognized as a chronic work-related stress problem by the World Health Organization in its International Classification of Diseases, is a common syndrome among practitioners. While it tends to occur in workers across various industries, medical and health workers, including nurses, are particularly susceptible (1, 2), Nurses, because of their direct and constant interaction with patients and families, coupled with high-intensity and complex nursing tasks, often experience higher levels of burnout compared to other medical professionals (3). A systematic review revealed that 28% of nurses experienced high emotional exhaustion, 15% experienced high depersonalization, and 31% reported low personal accomplishment (4). Despite this, research on nurse burnout remains limited in China, despite the significant stressors nurses face due to the country’s large population and limited medical resources (5). With an increasing number of medical incidents adding to their burdens, nurses in China face significant physical and mental strain. Thus, the occupational burnout status of nurses warrants attention in China.

Childhood trauma refers to a variety of potentially persistent stressful or traumatic events that individuals experience physically, psychologically, and emotionally before the age of 16 (6). According to the life course theory, certain experiences or events can serve as turning points in an individual’s life trajectory, particularly when they occur during childhood or adolescence, significantly impacting the subsequent course of one’s life (7). Therefore, we hypothesized that nurses’ childhood traumatic experiences may impact their occupational burnout and different types of occupational burnout. However, there are few studies exploring this, indicating the need for further investigation.

The stress sensitivity theory posits that individuals who have experienced childhood trauma have lower stress thresholds and are more prone to experiencing adverse mental health outcomes, such as loneliness and depressive symptoms, compared to those who have not experienced childhood trauma (8). Studies (9, 10) have indicated that exposure to negative events in childhood, such as abuse and neglect, can elevate the risk of loneliness and depressive symptoms. Hence, it is plausible that nurses who have experienced more childhood trauma may be predisposed to developing loneliness and depressive symptoms. However, research on this relationship among nurses is scarce, leaving the effects of childhood trauma on loneliness, depressive symptoms, and occupational burnout uncertain.

Moreover, it is widely acknowledged that poor mental health, including loneliness and depressive symptoms, can heighten the risk of occupational burnout among nurses, encompassing emotional exhaustion and depersonalization (11, 12). Additionally, poor mental health may diminish nurses’ sense of personal accomplishment (13). According to the affective event theory, external encounters experienced by nurses can influence their emotional state and subsequently impact their work status and behavior (14, 15). A study conducted in Brazil found that nurses with depressive symptoms were 5.33 times more likely to experience occupational burnout (16), while a study in Chile revealed that nurses experiencing loneliness were less likely to achieve personal accomplishment (17). Therefore, it is conceivable that loneliness and emotional disturbance may mediate the relationship between childhood trauma and burnout among nurses.

In addition, numerous studies have underscored the profound association between loneliness and emotional disturbances, particularly anxiety and depressive symptoms. For instance, Creese et al. (2021) identified loneliness as a significant risk factor for anxiety and depression among the elderly, both before and after the COVID-19 pandemic (18). Furthermore, a 5-year longitudinal study conducted in Chicago revealed that loneliness serves as a predictor for subsequent escalation in depressive symptoms (19).

The purpose of this study is to investigate the chained mediation mechanism from childhood trauma to loneliness, depressive symptoms, and further to occupational burnout (including emotional disturbance, depersonalization, and overall burnout) among nurses in China. The ultimate goal is to deepen our understanding of the underlying mechanisms of occupational burnout and provide valuable insights to enhance the efficiency and effectiveness of nursing practices.

Data for this study were derived from a cross-sectional survey of nurses in Yunnan province, China. The participants were nurses working at 18 local governmental hospitals, excluding student nurses, who agreed to provide informed consent and were able to understand and complete the questionnaire. Recruitment took place in the Dehong districts of Yunnan province. Dehong, situated in southwest China, shares borders with Myanmar on its north, west, and south sides.

Participants were recruited using convenience sampling. An electronic questionnaire was distributed to nurses via the “Wenjuanxing” online platform for data collection. Trained researchers briefed each participant on the study, and the questionnaire link was distributed with the assistance of the nursing departments of each governmental hospital. The survey ensured anonymity and independence in responses, with any queries addressed by the investigators, and participants had the right to withdraw at any time. Ultimately, 1,965 nurses participated in the survey, with 90.3% (1,774) completing it. This study received approval from the Ethics Committee of Dehong People’s Hospital in China (Number: DYLL-KY032).

The demographic characteristics included age (classified in years), sex (male and female), ethnicity (Han and others), legal residence (urban and rural), education level (high school or lower and bachelor’s degree or above), marital status (married, unmarried, and divorced or other), monthly income (3,000 RMB or lower, 3,001–5,000 RMB, 5,001–7,000 RMB, and 7,000 RMB or higher), and work experience (classified in years).

Childhood trauma was measured by the Childhood Trauma Questinnaire Short Form (CTQ-SF) (6), which inquired about participants’ experiences before the age of 16. The scale includes items related to emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect. The CTQ-SF comprises 25 clinical items and three validity items. Each item (e.g., “I feel that someone in my family hates me”) is rated on a five-point Likert scale ranging from 1 (never) to 5 (always), with the total score ranging from 25 to 125. The Cronbach’s α coefficient for internal consistency in this study was 0.73.

The three-item loneliness scale was used to measure loneliness (20). Each item (e.g., “How often do you feel that you lack companionship?”) is rated on a three-point Likert scale ranging from 1 (hardly ever) to 3 (often), with the total score ranging from 3 to 9. Higher scores indicate a higher level of loneliness. The Cronbach’s α coefficient for internal consistency in this study was 0.83.

The nine-item Patient Health Questionnaire (PHQ-9) (21) was utilized to measure depressive symptoms. Each item is assessed using a four-point Likert scale ranging from 0 (not at all) to 3 (nearly every day), with the total score ranging from 0 to 27. A higher score indicates more severe depressive symptoms. The Cronbach’s α coefficient for internal consistency in this study was 0.91.

The generalized anxiety disorder-7 (GAD-7) (22) was employed to measure anxiety symptoms. Each item is assessed using a four-point Likert scale ranging from 0 (not at all) to 3 (nearly every day), with the total score ranging from 0 to 21. A higher score indicates more severe anxiety symptoms. The Cronbach’s α coefficient in this study was 0.93.

The Chinese version of the Maslach Burnout Inventory-Human Service Survey (MBI-HSS) (23, 24), which comprises three subscales, was used to measure occupational burnout among nurses. This study was granted permission by the Mind Garden company. The three subscales include emotional exhaustion (Cronbach’s alpha = 0.92, nine items, e.g., “I feel emotionally drained from my work”), personal accomplishment (Cronbach’s alpha = 0.83, eight items, e.g., “I have accomplished many worthwhile things in this job”), and depersonalization (Cronbach’s alpha = 0.87, five items, e.g., “I feel treated some recipients as if they were impersonal objects”). Each item is assessed using a seven-point Likert scale ranging from 0 (not at all) to 6 (nearly every day). The scores of the items in each subscale are summed to obtain the total score for each dimension.

Descriptive analyses (e.g., frequency, proportion, mean, and standard deviation) were employed to describe the sample characteristics. Pearson correlation was conducted to explore the relationships among childhood trauma, loneliness, emotional disturbance (depressive symptoms and anxiety symptoms), and the dimensions of MBI-HSS (emotional exhaustion, personal accomplishment, and depersonalization).

Mediation analysis was utilized to examine the mediating role of loneliness and emotional disturbance in the association between childhood trauma and the various dimensions of MBI-HSS (25, 26). Figure 1 illustrates the conceptual diagrams of the mediation model. A total of 3,000 bootstrap cycles were performed to compute the standardized total effect and indirect effect, along with standard errors and bias-corrected 95% confidence intervals. Indirect effects were calculated as the total effect minus the direct effect. All data analyses were conducted using AMOS version 24.0 and SPSS version 24.0 (IBM Inc., NY, USA).

Table 1 presents the socio-demographic characteristics and key variable outcomes of the participants. The mean age of the participants was 32.00 (SD = 7.99) years. The majority were women (93.9%), with over half identifying as Han and married. Nearly 65% had attained a bachelor’s degree or higher, and over half (77.60%) resided in rural areas. The mean scores for childhood trauma and loneliness were 36.86 (SD = 10.73) and 5.26 (SD = 1.55), respectively. The mean scores for depressive symptoms and anxiety symptoms were 7.42 (SD = 5.13) and 6.29 (SD = 4.32). Additionally, the mean scores for emotional exhaustion, personal accomplishment, and depersonalization were 20.19 (SD = 12.50), 28.61 (SD = 11.50), and 6.88 (SD = 6.57), respectively.

Results in Table 2 indicate that childhood trauma was positively correlated with loneliness (r = 0.290, p < 0.001), depressive symptoms (r = 0.290, p < 0.001), and anxiety symptoms (r = 0.271, p < 0.001). Among different types of occupational burnout, emotional exhaustion was positively correlated with childhood trauma (r = 0.198, p < 0.001), loneliness (r = 0.453, p < 0.001), depressive symptoms (r = 0.621, p < 0.001), and anxiety symptoms (r = 0.580, p < 0.001). Personal accomplishment was negatively correlated with childhood trauma (r = −0.229, p < 0.001), loneliness (r = −0.107, p < 0.001), depressive symptoms (r = −0.141, p < 0.001), and anxiety symptoms (r = −0.153, p < 0.001). Depersonalization was positively correlated with childhood trauma (r = 0.317, p < 0.001), loneliness (r = 0.366, p < 0.001), depressive symptoms (r = 0.510, p < 0.001), and anxiety symptoms (r = 0.463, p < 0.001).

Results in Table 3 and Figure 2A reveal that loneliness [indirect effect (95% CI) = 0.294 (0.262, 0.328)] and emotional disturbance fully mediated the association between childhood trauma [indirect effect (95% CI) = 0.228 (0.196, 0.270)] and emotional exhaustion. Similarly, results in Table 3 and Figure 2B indicate that loneliness [indirect effect (95% CI) = −0.042 (−0.072, −0.008)] and emotional disturbance partially mediated the association between childhood trauma [indirect effect (95% CI) = −0.020 (−0.039, 0.002)] and personal accomplishment. Moreover, results in Table 3 and Figure 2C demonstrate that loneliness [indirect effect (95% CI) = 0.221 (0.186, 0.255)] and emotional disturbance partially mediated the association between childhood trauma [indirect effect (95% CI) = 0.164 (0.132, 0.193)] and depersonalization. All models exhibit a good fit for the mediation modeling analysis. Additionally, the subscales (emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect) of CTQ-SF affect loneliness, emotional disturbance, and burnout. Please refer to Supplementary Table 1 for details.