BACKGROUND: Stigmatizing attitudes toward individuals with mental health conditions are common among healthcare professionals in primary healthcare (PHC) settings, posing a major barrier to early diagnosis, appropriate treatment, and recovery.

METHODS: This systematic review and meta-analysis evaluated the effectiveness of interventions aimed at reducing mental health-related stigma among PHC professionals (general practitioners, nurses, community health workers, and allied providers). Eligibility was restricted to interventional studies targeting PHC staff; non-clinical populations and students without clinical practice were excluded. Comparators included usual training, waitlist control, or pre-post evaluation. A systematic search of PubMed, Scopus, and Web of Science was conducted in accordance with PRISMA guidelines, and the protocol was registered in PROSPERO (CRD420251074412).

RESULTS: Twenty-five studies met the inclusion criteria, of which three contributed to the quantitative synthesis. Interventions included educational, contact-based, and multicomponent approaches. Risk of bias was assessed using tools appropriate to study design. Interventions generally improved knowledge and attitudes and, to a lesser extent, behavioral intentions. Meta-analysis of pre-post changes using the Opening Minds Scale for Health Care Providers (OMS-HC) demonstrated a significant reduction in stigma (MD = -0.27, 95% CI -0.40 to -0.14; < 0.001; I = 91%). A difference-in-differences analysis of studies with intervention and control groups confirmed this effect with moderate heterogeneity (MD = -0.18, 95% CI -0.25 to -0.11; < 0.0001; I = 50%).

CONCLUSIONS: Contact-based and multicomponent interventions were associated with stronger and more sustained effects. The main limitations of the evidence were short follow-up periods, reliance on self-reported outcomes, methodological heterogeneity, and the possibility of publication bias. Our findings suggest that reducing stigma among PHC professionals can enhance patient engagement, timely diagnosis, and quality of care in routine clinical practice.