RETRACTED: Effects of L-DOPA Monotherapy on Psychomotor Speed and [11C]Raclopride Binding in High-Risk Older Adults With Depression

Abstract

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of Biological Psychiatry Editor John H. Krystal, M.D., with agreement from all authors except Chen Chen and Emily Valente. These two co-authors moved and, with no forwarding information that was available or could be found, they were therefore unable to be contacted. The authors have uncovered irregularities and deviations from the approved protocol related to the work reported in this article. Treatment with antidepressant medications within the past 28 days was an exclusion criterion: “Subjects were excluded for… current treatment or treatment within the past 4 weeks with psychotropic or other medications known to affect dopamine.” Individuals taking an ineffective antidepressant medication who otherwise met study criteria were to undergo a study-supervised medication taper to discontinue their medication for the required period prior to study participation. The published article does not describe that a subgroup of participants (15 out of the 47 consented subjects) enrolled in the study while taking an ineffective antidepressant medication. Of this subgroup, 10 individuals were successfully tapered off their medication and were among the 36 subjects contributing data to the analyses described. In addition, the authors have found that 8 participants did not complete the required 28-day washout prior to beginning the study. For these 8 participants, the medication-free period ranged from 1 to 21 days, with a mean of 10.1 days. Separately, an inclusion criterion was that eligible subjects “had Center for Epidemiologic Studies—Depression Rating scale score ≤ 10.” However, the authors have found that 3 ineligible participants were included, each of whom had depressive symptom scores 1 point out of range for eligibility. Lastly, the CONSORT diagram in Figure S1 states that 11 participants were lost to follow-up. However, this is incorrect. Instead, 9 participants were lost to follow up and 2 participants were screen failures. The authors voluntarily informed the Journal of these honest errors upon discovery. Because of the extent of these issues, the editors and authors concluded that the only course of action was to retract this paper. However, the authors are revising the paper, which the Journal will consider further for publication.

Trial registration: ClinicalTrials.gov NCT02744391.

Keywords: Gait speed; Late-life depression; Levodopa; Positron emission tomography; Processing speed; Raclopride.

Figure 1.

Baseline (Week 0) and post-L-DOPA (Week 3) mean [¹¹C]raclopride binding (N=10). To the left, mean sagittal, coronal, and transverse images for [¹¹C]raclopride PET and structural MRI are shown. Canonical striatal brain regions demonstrating [¹¹C]raclopride are evident. To the right, mean changes from pre- to post-L-DOPA in [¹¹C]raclopride BP_ND are provided. Significantly decreased [¹¹C]raclopride was observed in sensorimotor striatum (SMST) and associative striatum (AST), but not limbic striatum (LST).