Abstract
Long-acting injectable (LAI) antipsychotics are increasingly utilized to address non-adherence and improve clinical stability in patients with chronic psychiatric disorders. However, real-world data comparing different LAI formulations remain limited. This retrospective mirror-image study evaluated the clinical effectiveness of LAI antipsychotics among 149 individuals who received treatment at a community mental health center. Clinical outcomes, including hospitalizations, duration of hospitalization, psychiatric emergency visits, and relapses, were compared across equal-length pre- and post-treatment periods. Following LAI initiation, significant reductions were observed in hospitalizations, emergency visits, and relapse rates across the full sample (p < .001). Cox regression analyses revealed that LAI treatment was associated with a lower hazard of hospitalizations, emergency visits, and relapses. Comparative analyses among LAI formulations showed that while all agents were effective, paliperidone palmitate 1-month (PP1M) and aripiprazole once-monthly (AOM) were associated with greater improvements in acute service utilization than paliperidone 3-month (PP3M). Furthermore, AOM was linked to significantly lower concurrent oral antipsychotic use despite similar total antipsychotic doses. These findings suggest that LAI antipsychotics offer substantial benefits in reducing healthcare utilization and enhancing clinical outcomes in real-world psychiatric care. PP1M and AOM may offer superior effectiveness in certain clinical domains, although prospective controlled studies are warranted to confirm formulation-specific advantages. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-026-07801-y.