Skip to main content Accessibility help

Validation of the semi-structured Psychotic Depression Assessment Scale (PDAS) interview

  • Rugül Köse Çinar (a1) and Søren Dinesen Østergaard (a2)



Recently, a semi-structured interview dedicated to aid rating on the Psychotic Depression Assessment Scale (PDAS) was developed. Here, we aimed to validate PDAS ratings collected via this semi-structured interview.


A total of 50 patients with psychotic depression – 34 with unipolar psychotic depression and 16 with bipolar psychotic depression – were recruited for the study. The following aspects of validity were investigated: clinical validity, psychometric validity (scalability), and responsiveness.


The PDAS ratings were clinically valid (Spearman’s coefficient of correlation between PDAS total scores and Clinical Global Impressions scale – severity of illness ratings=0.66, p<0.001), scalable (Loevinger’s coefficient of heterogeneity at endpoint=0.45), and responsive (no participants met the criterion for remission on the PDAS (total score <8) at baseline – at endpoint 74% (95% CI: 60–85) of the participants met this criterion).


The semi-structured PDAS interview provides valid ratings of the severity of psychotic depression.


Corresponding author

*Rugül Köse Çinar, MD, Department of Psychiatry, Trakya University Hospital, Edirne, Turkey. Tel: 905337330407; Fax: 902842353451; E-mail:


Hide All
1. Rothschild, AJ. Clinical manual for diagnosis and treatment of psychotic depression. Washington, DC, USA: American Psychiatric Publishing Inc., 2009.
2. Ostergaard, SD, Leadholm, AK, Rothschild, AJ. Persistent delusional theme over 13 episodes of psychotic depression. Acta Neuropsychiatr 2013;25:370373.
3. Gesi, C, Carmassi, C, Miniati, M, Benvenuti, A, Massimetti, G, Dell’Osso, L. Psychotic spectrum symptoms across the lifespan are related to lifetime suicidality among 147 patients with bipolar I or major depressive disorder. Ann Gen Psychiatry 2016;15:15.
4. Zalpuri, I, Rothschild, AJ. Does psychosis increase the risk of suicide in patients with major depression? A systematic review. J Affect Disord 2016;198:2331.
5. Leadholm, AK, Rothschild, AJ, Nielsen, J, Bech, P, Ostergaard, SD. Risk factors for suicide among 34,671 patients with psychotic and non-psychotic severe depression. J Affect Disord 2014;156:119125.
6. Ostergaard, SD, Rothschild, AJ, Flint, AJ et al. Rating scales measuring the severity of psychotic depression. Acta Psychiatr Scand 2015;132:335344.
7. Ostergaard, SD, Meyers, BS, Flint, AJ et al. Measuring psychotic depression. Acta Psychiatr Scand 2014;129:211220.
8. Meyers, BS, Flint, AJ, Rothschild, AJ et al. A double-blind randomized controlled trial of olanzapine plus sertraline vs olanzapine plus placebo for psychotic depression: the study of pharmacotherapy of psychotic depression (STOP-PD). Arch Gen Psychiatry 2009;66:838847.
9. Ostergaard, SD, Meyers, BS, Flint, AJ et al. Measuring treatment response in psychotic depression: the Psychotic Depression Assessment Scale (PDAS) takes both depressive and psychotic symptoms into account. J Affect Disord 2014;160:6873.
10. Bech, P, Gram, LF, Dein, E, Jacobsen, O, Vitger, J, Bolwig, TG. Quantitative rating of depressive states. Acta Psychiatr Scand 1975;51:161170.
11. Hamilton, M. Development of a rating scale for primary depressive illness. Br J Soc Clin Psychol 1967;6:278296.
12. Overall, JE, Gorham, DR. The Brief Psychiatric Rating Scale. Psychol Rep 1962;10:799812.
13. Ostergaard, SD, Pedersen, CH, Uggerby, P et al. Clinical and psychometric validation of the psychotic depression assessment scale. J Affect Disord 2015;173:261268.
14. First, MB, Spitzer, RL, Gibbon, M, Williams, JBW. Structured clinical interview for DSM-IV axis I disorders, clinician version (SCID-CV). Washington, DC: American Psychiatric Press, 1996.
15. Guy, W. editor Clinical global impressions scale. In: ECDEU assessment manual for psychopharmacology. Rockville, MD, USA: US Department of Health, Education and Wel-fare publication no. (AMD) 76-338, NIMH, 1976.
16. Mokken, R. Theory and practice of scale analysis. Berlin, Germany: Mouton, 1971.
17. Loevinger, J. Objective tests as instruments of psychological theory. Biol Psychiatry 1957;3:249252.
18. Ostergaard, SD, Rothschild, AJ, Flint, AJ et al. Establishing the cut-off score for remission and severity-ranges on the Psychotic Depression Assessment Scale (PDAS). J Affect Disord 2016;190:111114.
19. Molenaar, IW, Debels, P, Sijtsma, K. User’s Manual MSP: a program for Mokken Scale Analyses for Polytomous Items (Version 3.0). Groeningen, the Netherlands: ProGAMMA, 1994.
20. Ostergaard, SD, Bertelsen, A, Nielsen, J, Mors, O, Petrides, G. The association between psychotic mania, psychotic depression and mixed affective episodes among 14,529 patients with bipolar disorder. J Affect Disord 2013;147:4450.
21. Ostergaard, SD, Petrides, G, Dinesen, PT et al. The association between physical morbidity and subtypes of severe depression. Psychother Psychosom 2013;82:4552.
22. Loo, CK, Mahon, M, Katalinic, N, Lyndon, B, Hadzi-Pavlodic, D. Predictors of response to ultrabrief right unilateral electroconvulsive therapy. J Affect Disord 2011;130:192197.
23. Petrides, G, Fink, M, Husain, MM et al. ECT remission rates in psychotic versus nonpsychotic depressed patients: a report from CORE. J ECT 2001;17:244253.
24. Leadholm, AK, Rothschild, AJ, Nolen, WA, Bech, P, Munk-Jorgensen, P, Ostergaard, SD. The treatment of psychotic depression: is there consensus among guidelines and psychiatrists? J Affect Disord 2013;145:214220.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Acta Neuropsychiatrica
  • ISSN: 0924-2708
  • EISSN: 1601-5215
  • URL: /core/journals/acta-neuropsychiatrica
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed