Blinded Assessment and Independent Rating

The manuals converge on the need to keep outcome rating separate from treatment delivery and other clinical roles. Across the extracts, blinded or independent assessors are used to reduce bias, preserve the integrity of efficacy ratings, and protect outcome validity, with particular emphasis on maintaining assessor blinding and avoiding involvement in treatment decisions for the same participant. They also agree on practical safeguards for independence, including clear separation from other study assessments, avoiding disclosure of treatment allocation or safety and treatment details, and protecting confidentiality. Several sources also note the value of consistency in rater assignment when possible, and one manual explicitly links blinded ratings to the primary and key secondary endpoints through the MADRS total score. The manuals differ in emphasis and setting. The esketamine trial focuses most directly on blinded clinician-rated MADRS assessments in an open-label design, including timing around dosing and PROs. The MDMA trial places more weight on confidentiality, separate clinical and outcome databases, and preventing contamination of blinded assessment processes. The 5-MeO-DMT trial highlights masking dose identity until study completion when applicable, and specifically notes that assessors should not witness dose administration and may be remote raters not involved in patient care.