Establishing the cut-off score for remission and severity-ranges on the Psychotic Depression Assessment Scale (PDAS).
BACKGROUND
The Psychotic Depression Assessment Scale (PDAS) is a rating scale dedicated to the measurement of severity in psychotic depression (PD). The aim of this study was to establish the PDAS cut-off for remission of PD as well as PDAS score-ranges for mild, moderate, and severe PD. The secondary aim was to test how remission, as defined by the PDAS, would perform as outcome measure when applied to the data from a large randomized controlled trial (RCT) in PD.


METHODS
The study was based on data from the Study of Pharmacotherapy in Psychotic Depression (STOP-PD). The cut-off for remission on the PDAS and the severity-ranges for mild, moderate, and severe PD were defined using the Clinical Global Impression - Severity scale (CGI-S) as reference by means of pair-wise receiver operating characteristic (ROC) analyses. Subsequently, it was tested whether remission on the PDAS could separate the effects of Olanzapine+Sertraline vs. Olanzapine+Placebo through an intention-to-treat, mixed-effects logistic regression of the data from STOP-PD.


RESULTS
According to the ROC analyses, the ideal cut-off for remission of PD was a PDAS total score <8, while the severity-ranges for mild, moderate and severe PD were 8-15, 16-23, and >23 respectively. When applying the PDAS total score <8 (remission) as outcome on the STOP-PD data, treatment with Olanzapine+Sertraline performed significantly better than Olanzapine+Placebo (p<0.001).


CONCLUSIONS
The STOP-PD was not designed specifically to answer the research questions of the present study.


CONCLUSIONS
According to this study, a total score <8 on the PDAS corresponds to remission of PD.
Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; Department P - Research, Aarhus University Hospital-Risskov, Risskov, Denmark. Electronic address: soeoes@rm.dk.
Søren D
SD
Østergaard
University of Massachusetts Medical School and University of Massachusetts Memorial Health Care, Worcester, MA, USA.
Anthony J
AJ
Rothschild
Department of Psychiatry, University Health Network, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
Alastair J
AJ
Flint
Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Western Psychiatric Institute and Clinic, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Benoit H
BH
Mulsant
Western Psychiatric Institute and Clinic, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Ellen M
EM
Whyte
Collaborative Antwerp Psychiatric Research Institute, Psychiatric Hospital Duffel, Duffel, Belgium.
Tom
T
Vermeulen
Psychiatric Research Unit, Psychiatric Center North Zealand, Copenhagen University Hospital, Hillerød, Denmark.
Per
P
Bech
Department of Psychiatry, Weill Medical College of Cornell University and New York Presbyterian Hospital, Westchester Division, White Plains, NY, USA.
Barnett S
BS
Meyers
D000928:Antidepressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001569:Benzodiazepines / Q000008:administration & dosage / Q000627:therapeutic use; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D000077152:Olanzapine; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D016032:Randomized Controlled Trials as Topic; D012074:Remission Induction; D020280:Sertraline / Q000008:administration & dosage / Q000627:therapeutic use; D012720:Severity of Illness Index
D000928:Antidepressive Agents; D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000077152:Olanzapine; D020280:Sertraline
Affective disorders; Antidepressive agents; Antipsychotic agents; Psychiatric status rating scales; Psychotic; Remission induction