Retraction to: Neuropsychopharmacology https://doi.org/10.1038/s41386-020-00860-z, published online 12 September 2020

The authors have retracted this article because they have found deviations from the approved protocols supplying data for this analysis. These issues were restricted to procedures for ascertaining eligibility and did not affect the MRI acquisition or data analysis. This analysis aggregated data across two studies in order to investigate the association of neuromelanin (NM)-MRI signal with baseline psychomotor speed, assess whether baseline NM-MRI signal predicts treatment response to levodopa (LDOPA), and evaluate whether subacute LDOPA treatment affects NM-MRI signal. The constituent studies both recruited depressed older adults, and current treatment with antidepressant medications was an exclusion criterion in each. The deviations from the approved protocols were as follows:

  • Study 1 had an exclusion criterion for current antidepressant treatment, but there was no requirement for a 28-day medication-free period. The exclusion criterion for Study 2 required participants to be free of antidepressant or psychotropic medications for 28 days. This distinction is not clear in the published study methods.

  • The article does not report that eight out of the 33 individuals contributing data to the analyses enrolled in the study while taking an ineffective antidepressant medication and were successfully tapered off their medication prior to beginning study procedures.

  • In addition three tapered individuals in Study 2 did not complete the required 28-day washout prior to beginning the study (for these three, the medication-free period had a range 1–20 days and a mean of 8.0 days).

  • Unrelated to medication taper and washout, two participants in Study 2 had depressive symptom scores one point out of range for eligibility.

All authors agree with this retraction.