The global burden of mental disorders, including schizophrenia, is substantial, impacting health, social well-being, and economies. In China, where family caregiving is prevalent due to resource limitations and cultural factors, family caregivers of individuals with schizophrenia experience significant burden, encompassing psychological, social, physical, and financial challenges. This burden negatively affects the quality of care and the patient's recovery. While previous research identified disease-related factors (patient disability, aggressive behaviors) and caregiver-related factors (low social support, perceived stigma) as associated with increased caregiver burden, the underlying mechanisms remain unclear. This study aimed to investigate the associations and mediating mechanisms between patient disability and caregiver burden, hypothesizing that: (a) disability directly affects caregiver burden; and (b) disease-related stressors (potentially harmful patient behavior) and caregiver-related stressors (social support and affiliate stigma) mediate this association.

Existing literature highlights the association between patient disability and caregiver burden in schizophrenia. Studies indicate that higher levels of patient disability correlate with increased caregiver burden. Additionally, research shows that caregiver-related factors such as low social support and perceived stigma are associated with higher caregiver burden. However, there is a scarcity of studies exploring the interplay between these disease-related and caregiver-related factors in shaping caregiver burden, especially within the context of Chinese families. Pearlin's caregiver stress model suggests that patient behavior problems create secondary stressors for caregivers, leading to increased burden. This study aims to fill this gap in the literature by examining the mediating roles of potentially harmful patient behavior, caregiver affiliate stigma, and social support in the relationship between patient disability and caregiver burden among Chinese families.

A cross-sectional study was conducted between April 2021 and March 2022 in four Chinese cities (Wuhan, Changsha, Guangzhou, and Shenzhen). The sample consisted of 493 patient-caregiver dyads from 45 randomly selected community health centers. Inclusion criteria for patients included age ≥18, a clinical diagnosis of schizophrenia (ICD-10), ability to communicate in Chinese, and living with family members. Caregiver inclusion criteria were age ≥16, primary caregiver responsibility, and ability to communicate in Chinese. Data were collected using standardized questionnaires: the Zarit Burden Interview (ZBI-22) for caregiver burden; the WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) for patient disability; the Potentially Harmful Behavior Scale (PHBS) for patient behavior; the Affiliate Stigma Scale (ASS) for caregiver stigma; and the Multidimensional Scale of Perceived Social Support (MSPSS) for caregiver social support. Sociodemographic data for both patients and caregivers were also collected. Data analysis involved linear regression analysis to examine associations between patient disability and caregiver burden, controlling for potential confounders. Structural equation modeling (AMOS 23.0) and bootstrapping analysis were used to assess mediation effects of potentially harmful behavior, affiliate stigma, and social support.

The study found that patient disability was significantly associated with higher caregiver burden (B = 0.616; 95% CI: 0.479–0.753). Other factors significantly associated with higher caregiver burden included: potentially harmful patient behavior (B = 0.474; 95% CI: 0.232–0.716), low caregiver social support (B = −0.079; 95% CI: −0.158–−0.002), and high caregiver affiliate stigma (B = 13.045; 95% CI: 10.227–15.864). Mediation analysis revealed that patient disability indirectly affected caregiver burden through several pathways: (1) patient disability leading to increased potentially harmful behavior, subsequently increasing caregiver burden (β=0.049, p<0.01, PM 9.12%); (2) patient disability leading to increased potentially harmful behavior, then increased affiliate stigma, and finally higher caregiver burden (β=0.026, p<0.01, PM=4.84%); (3) patient disability leading to increased affiliate stigma, resulting in higher caregiver burden (β=0.036, p<0.05, PM=6.70%); (4) patient disability leading to decreased social support, subsequently increasing affiliate stigma and caregiver burden (β=0.029, p<0.01, PM=5.40%); and (5) patient disability leading to decreased social support, directly increasing caregiver burden (β=0.026, p<0.05, PM=4.84%). The direct effect of patient disability on caregiver burden remained significant even after accounting for mediating variables (β=0.371, p < 0.001).

The findings confirm the strong association between patient disability and caregiver burden, consistent with previous research. The significant mediating roles of potentially harmful behavior, affiliate stigma, and social support highlight the complex interplay of factors contributing to caregiver burden. The impact of potentially harmful behavior underscores the need for interventions to manage patient aggression and violence. The significant role of affiliate stigma emphasizes the importance of reducing stigma towards individuals with schizophrenia and their families. The negative mediating effect of social support highlights the crucial role of providing social support networks for caregivers. These findings have important implications for developing culturally sensitive interventions targeting these mediating factors to reduce caregiver burden.

This study demonstrates that patient disability significantly contributes to caregiver burden, and this relationship is mediated by potentially harmful patient behavior, caregiver affiliate stigma, and social support. Future interventions should focus on improving patient functioning, reducing potentially harmful behaviors, addressing caregiver stigma, and bolstering social support networks. Longitudinal studies are needed to confirm causal relationships and evaluate the effectiveness of such interventions. Further research should also investigate the role of coping mechanisms and cultural factors in modulating the relationship between patient disability and caregiver burden.

The cross-sectional design limits causal inferences. While efforts were made to maximize participation, refusal rates could have biased the sample. The reliance on self-reported data may be subject to recall bias and social desirability bias. Future longitudinal studies are warranted to establish causality and explore the dynamic interplay of these factors over time.