Convergent validity and responsiveness of the patient-reported depression checklist (PRDC) in treatment-resistant depression

Background Major depressive disorder is characterized by substantial heterogeneity in symptom presentation and functional impairment, which are not fully captured by existing clinician- and patient-reported outcome measures. The Patient-Reported Depression Checklist (PRDC) may address limitations of commonly used symptom assessments. Methods Post hoc analyses from the ENLIGHTEN-randomized, placebo-controlled trial of liafensine (1 or2 mg/day) were performed in 188 patients with treatment resistant depression. Baseline convergent validity was assessed between PRDC Frequency, Impact, and Overall Impact scores against established clinical assessments, including the Montgomery-Asberg Depression Rating Scale (MADRS), the Clinical Global Impression-Severity (CGI-S), Clinical Global Impression-Improvement (CGI-I) and the Sheehan Disability Scale (SDS). Longitudinal convergent responsiveness was evaluated using correlations between change from baseline in PRDC scores and comparator measures. Results At baseline, PRDC Frequency, Impact and Overall Impact scores demonstrated moderate correlations with CGI-S and MADRS scores across treatment groups (r = 0.33–0.6; all p ≤ 0.006). By Day 7, PRDC scores showed moderate-to-strong longitudinal responsiveness (r = 0.26–0.65; all p < 0.001), with consistent patterns across treatment groups. In comparison, PRDC Frequency and Impact scores demonstrated consistent treatment effect sizes (d = 0.47 and 0.48, respectively), numerically greater than MADRS (d = 0.39), CGI-I (d = 0.35), and CGI-S (d = 0.28), all comparisons p ≤ 0.002. Limitations The PRDC was evaluated as a secondary/post hoc analysis within a single clinical trial, and not through a dedicated prospective psychometric validation study. Conclusions The PRDC demonstrated convergent validity with established clinician-rated measures and was responsive to both early and sustained treatment-related change. The PRDC captured valuable patient-reported effects on symptom frequency and functional impact which are increasingly sought by clinicians and regulators.