No clinically meaningful difference detected in trajectories of family burden in adults with schizophrenia receiving community-based rehabilitation: a 48-week prospective cohort study of long-acting injectable versus oral antipsychotics

Family caregivers of individuals with schizophrenia assume substantial financial, physical, and psychosocial responsibilities, particularly in Asian family systems. Long-acting injectable (LAI) antipsychotics may improve adherence and reduce caregiving demands, but their incremental benefit over oral antipsychotics (OAP) in structured community mental health settings remains unevaluated. We conducted a 48-week prospective cohort study within routine community mental health services in four cities in Guangdong, China (April 2023–December 2024), under full government reimbursement for paliperidone palmitate LAI. Community-dwelling adults with schizophrenia receiving LAI ( n = 270) or OAP ( n = 268) were enrolled; treatment allocation was based on routine clinical decision-making. Family caregiver burden (24-item Family Burden Interview Schedule, FBIS-24), psychiatric symptoms (Positive and Negative Syndrome Scale, PANSS), and social functioning (Personal and Social Performance Scale, PSP) were assessed at five time points. Linear mixed-effects models with multiplicity-adjusted inference were applied, and burden domain analyses were conducted on an exploratory basis. Among 538 participants (86.8% retained), caregiver burden decreased substantially in both groups: adjusted FBIS-24 total scores fell from 9.16 to 6.32 in the OAP group (31.0%) and from 9.09 to 5.53 in the LAI group (39.2%). No treatment-by-time interaction was significant after multiplicity adjustment (all adjusted p > 0.05; f² ≤ 0.003), and every multiplicity-adjusted 95% confidence interval lay within the ± 2.4-point clinical-relevance bound. Exploratory burden domain differences favoring LAI at 48 weeks in family leisure, family interaction, and mental health were nominally significant but negligible ( f² ≈ 0.005), and none survived correction across the full exploratory family. Psychiatric symptoms and social functioning improved in both groups, without detectable between-group differences. Sensitivity analyses, including propensity-score overlap weighting, agreed. In a structured community-based mental health program with full LAI reimbursement, clinically stable adult outpatients receiving LAI or OAP experienced substantial reductions in caregiver burden, with no clinically meaningful difference detected between formulations over 48 weeks. In this setting, formulation choice did not differentiate caregiver burden trajectories; exploratory domain signals were hypothesis-generating only. Whether LAI treatment reduces caregiver burden where it is not fully subsidized, or in acutely ill or poorly adherent patients, remains to be determined.