To the Editor In their article in JAMA Psychiatry, Rutherford et al1 observed that the average change associated with placebo treatment in antipsychotic trials has risen since 1960. Moreover, they reported that the average difference between drug and placebo outcomes has significantly decreased over time, with reduced baseline severity and greater study duration. To evaluate drug efficacy in patients with schizophrenia, Rutherford et al1 used a standardized mean change score, which was determined by dividing the mean pre-post difference by the number of total possible points of the scale being used. Overall, they attributed their findings to modifications in randomized clinical trials that have contributed to inflated baseline scores, enrollment of less severely ill patients, and higher expectations of the study participants.
Lozano R. Measuring the Effects of Treatment With Antipsychotics. JAMA Psychiatry. 2015;72(5):514. doi:10.1001/jamapsychiatry.2014.3130