Background: This report builds on a previous analysis examining the long-term effects of a placebo period on a group of inpatients with chronic schizophrenia. In the present analysis, outcome was evaluated through the use of the Psychiatric Adverse Events Rating Scale.
Methods: This retrospective analysis examined adverse events for 55 patients with chronic schizophrenia who were placed in a double-blind placebo study on the inpatient units of the National Institute of Mental Health Neuropsychiatric Research Hospital. The number and severity of adverse events experienced by these patients during baseline, placebo, and discharge periods were analyzed.
Results: The frequency and severity of adverse events for this group of patients were modest. Most patients did not experience a statistically significant increase in adverse events during their placebo phase; however, a subgroup of patients who were hospitalized for less than 2 months after antipsychotic medications were restored did experience a statistical elevation in adverse events, and that frequency remained statistically elevated at discharge.
Conclusions: The results confirm the findings from our previous analysis. Regardless of whether outcome is measured by a behavioral rating scale or by an adverse event scale, given a sufficiently lengthy recovery period, patients with chronic schizophrenia who go through a placebo phase return to baseline.