OBJECTIVES: No Minimum Clinically Important Difference (MCID) for the Calgary Depression Scale for Schizophrenia (CDSS) has been reported yet. This scale, ranging from 0 to 27, assesses the level of depression in schizophrenia. The objective of this study was to generate a MCID for the CDSS, based on a longitudinal cohort of patients with schizophrenia. METHODS: Two methods exist to assess MCID in scales such as CDSS: the anchor-based approach (comparison of the change in CDSS score and Clinical Global Impression (CGI) within- and between-patients), and the distribution-based approach (comparison between the change in PRO scores and some measure of variability, including standard error measurement approach, standard deviation approach and effect size). Both methods were implemented in a longitudinal cohort of patients with schizophrenia. RESULTS: