Development, Feasibility, and Appreciation of the Collaborative Integrated Depression Care (IDECA) Project in Flanders, Belgium

<b>Background</b>: Depression remains a major global health burden, yet fragmented care often leads to waiting times and unmet needs. Therefore, the Belgian collaborative Integrated Depression Care (IDECA) project strengthened primary care depression management by introducing a Reference Person Mental Wellbeing (RPMW) who functions as a case manager, supported by shared-care tools, structured psychoeducation modules, and targeted training for general practitioners (GPs). This study examines normalization in primary care practice. <b>Methods</b>: A single-arm, mixed-method study was implemented over 18 months in two Flemish Primary Care Zones (PCZ). Implementation outcomes were assessed every four months using the NoMAD questionnaire and analyzed using Wilcoxon signed-rank tests. Peer review sessions with professionals and interviews with patients were analyzed thematically. Caseload and service delivery were assessed using process evaluation logs. <b>Results</b>: Twenty-two professionals (17 GPs, two RPMWs, and three PCZ staff members) completed the NoMAD questionnaire. Intervention familiarity increased during the first eight months (T0-T1: <i>p</i> < 0.001; T1-T2: <i>p</i> = 0.022) and continued to rise thereafter (T3-T4: <i>p</i> = 0.008). Integration into daily practice and perceived impact on professional work improved progressively, reaching near-ceiling scores. Peer review sessions highlighted the RPMW's central role in trust-building and care coordination. Over 12 months, one full-time equivalent RPMW supported 175 patients (mean age 40.7 years; 75% female), with an average of five consultations per patient. Patients reported high satisfaction, emphasizing accessibility, empathy, and practical support. <b>Conclusions</b>: Sustained results suggest successful normalization and support the potential of collaborative, low-threshold depression care. Future work will assess clinical and economic outcomes.