Mitigating Involuntary Psychiatric Admissions and Enhancing Well-Being via Long-Acting Injectables: A Six-Month Contrast of Two Cognitively Impaired Community Subcohorts

Background: Managing comorbid psychotic disorders and cognitive impairments in community settings is clinically challenging. This study evaluates the real-world outcomes associated with long-acting injectable (LAI) antipsychotics regarding psychiatric hospitalizations, clinical severity, and quality of life (QoL) in community-dwelling patients with intellectual or cognitive deficits. Methods: A retrospective, uncontrolled pre–post cohort study was conducted analyzing observational data from 41 patients enrolled in the “DNAng” research project over a six-month observation window. The sample was stratified into two subgroups: a non-hospitalized cohort with primary intellectual disabilities (n = 22) and a previously hospitalized cohort characterized by cognitive decline and dual diagnoses (n = 19). Main outcomes were tracked using the Clinical Global Impression-Severity (CGI-S) scale and the WHOQOL-BREF Global QoL item. Results: Baseline χ2 testing revealed significant sociodemographic and diagnostic differences between the subcohorts (p < 0.05). Following LAI initiation, both groups demonstrated statistically significant longitudinal changes. In the non-hospitalized group, CGI-S scores decreased from 5.77 ± 0.86 to 3.09 ± 0.92 (unadjusted p < 0.001; paired Cohen’s d = 3.01, 95% CI: [2.03, 3.99]) and QoL scores rose from 0.59 ± 0.50 to 3.13 ± 0.83 (unadjusted p < 0.001; paired Cohen’s d = −3.71, 95% CI: [−4.88, −2.53]). In the previously hospitalized group, total admissions decreased from a baseline median of 2.0 (IQR: 1.0–3.0) to a post-treatment median of 0.0 (IQR: 0.0–0.0) (Wilcoxon unadjusted p = 0.0002; paired Cohen’s d = 2.23, 95% CI: [1.39, 3.07]), accompanied by an observed decline in involuntary prosecutor-ordered admissions. Furthermore, CGI-S scores decreased to 3.78 ± 1.08 (unadjusted p = 0.0003; paired Cohen’s d = 2.22, 95% CI: [1.38, 3.06]), and QoL scores reached 3.05 ± 0.84 (unadjusted p = 0.0001; paired Cohen’s d = −3.64, 95% CI: [−4.88, −2.40]). Conclusions: In this retrospective evaluation, LAI antipsychotic administration was accompanied by observed reductions in clinical severity, concurrent improvements in subjective well-being scores, and lower rates of involuntary hospitalizations within this cognitively vulnerable population. These findings indicate an association between LAI formulations and clinical stability in community psychiatry, though controlled prospective studies remain essential to establish causal links.