<p>The COVID-19 pandemic amplified an ongoing mental health crisis in Europe. In response, the Italian Ministry of Health introduced the “Psychological Bonus,” a government-funded initiative aimed at improving access to brief psychological interventions (BPIs). This longitudinal study examined the effectiveness of these publicly funded BPIs in reducing psychological distress, anxiety, and depression among a large sample of Italian patients, while also exploring the moderating roles of therapy continuation, therapist orientation, and treatment setting. A total of 1,541 participants were assessed at baseline (T0), post-treatment (T1), and six-month follow-up (T2) using the CORE-10, GAD-7, and PHQ-9. Longitudinal trajectories were analyzed using Linear Mixed Models, controlling for age, sex, and session count. Separate models examined the impact of therapy continuation, therapist orientation, and treatment setting (in-person, online, or blended). Significant reductions in psychological distress, depression, and anxiety from baseline to post-treatment were maintained at follow-up, with effect sizes ranging from medium to large across outcomes and timepoints (d = 0.54–0.80). A small but significant attenuation of psychological distress gains was observed between post-treatment and follow-up, while depression and anxiety scores remained stable. Continuation of therapy after the funded sessions did not significantly moderate symptom trajectories. Likewise, no significant differences in change trajectories emerged across therapist theoretical orientations or treatment settings. The findings provide strong support for the effectiveness of the “Psychological Bonus” as a publicly funded BPI, helpful in addressing widespread mental health needs across different therapeutic and delivery models, representing a promising model for mental health policy.</p>