Questions:  What is the magnitude of learning effects in patients with schizophrenia receiving placebo on the criterion standard Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB), and can these learning effects be anticipated in individual patients?

Findings:  This blinded review of 12 trials including 813 patients with schizophrenia suggested that the mean change in the MCCB during receipt of placebo was less than 0.2 SDs, a small effect. Factors associated with greater improvements on the MCCB included more motivation, more depression/anxiety, and less improvement from screening to baseline.

Meaning: These changes in the MCCB are too small to be responsible for effective active treatments failing to separate from placebo.

View the article at Jama Psychiatry.

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