Brief report Psychometric properties of the dutch version of the core measure of melancholia Didi Rhebergen a,b,n , Derk L. Arts b , Hannie Comijs a,b , Aartjan T.F. Beekman a,b , Caroline B. Terwee c , Gordon Parker d , Max L. Stek a,b a Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, The Netherlands b GGZ inGeest, Amsterdam, The Netherlands c Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, The Netherlands d School of Psychiatry, University of NSW, and Black Dog Institute, Sydney, Australia article info Article history: Received 30 December 2011 Received in revised form 14 March 2012 Accepted 14 March 2012 Available online 9 August 2012 Keywords: Reliability Validity Instruments Depression Psychomotor symptoms CORE abstract Background: The CORE measure was designed to assess psychomotor symptoms and the probability of melancholia in depressed people. We tested the inter-rater reliability and validity of the Dutch version of the CORE. Methods: Thirty-seven elderly, depressed in-patients were studied. The CORE, Salpˆ etri  ere Retardation Rating Scale (SRRS), Quick Inventory of Depressive Symptoms-self-report version (QIDS) and Mon- tgomery Asberg Depression Rating Scale (MADRS) were administered. The inter-rater reliability of the CORE was examined by calculating the intra-class correlation coefficient (ICC) of agreement between five independent raters. Construct validity was assessed by calculating Spearman rho (r) correlations between CORE and SRRS, QIDS and MADRS measure scores. Results: The ICC for total CORE scores was 0.80, while, for the CORE sub-scales the ICCs were 0.74 for non-interactiveness, 0.70 for retardation and 0.79 for agitation, indicating high inter-rater reliability. Associations between the CORE and SRRS measures supported the validity of the CORE as a measure of psychomotor disturbance, while correlations between the CORE agitation sub-scale and agitation items derived from the QIDS and MADRS were low to moderate. Limitations: Both the sample size and the comparator measures of psychomotor disturbance (especially agitation) may have compromised construct validity analyses. Conclusions: High inter-rater reliability was demonstrated for the Dutch CORE measure. Its validity as a measure of psychomotor disturbance was supported in analyses involving total CORE scores. & 2012 Elsevier B.V. All rights reserved. 1. Introduction Melancholic depression has long had a number of ascriptions (Parker and Hadzi-Pavlovic, 1996a), including distinctive clinical features, the primacy of biological causes and a preferential response to somatic as against psychotherapeutic treatments. For centuries, melancholia was more viewed as a movement disorder rather than as a mood disorder (Berrios, 1988). While the primacy and specifi- city of psychomotor symptoms and signs to melancholic depression was long weighted by observers (Parker and Brotchie, 1996; Shorter, 2007; Sobin and Sackeim, 1997), such features are underrepresented in the DSM delineation of the melancholia specifier (American Psychiatric Association, 1980, 1987, 1994, 2000). In addition, few instruments have been developed specifically for quantifying psy- chomotor features, so that such features are usually abstracted from more generic depression severity measures, such as the Hamilton Depression Rating Scale (Schrijvers et al., 2007). Exceptions include the Salpˆ etri  ere Retardation Rating Scale (SRRS) (Widl ¨ ocher and Ghozlan, 1989) and the Motor Agitation and Retardation scale or MARS (Sobin et al., 1998), however, the SRRS only measures psychomotor retardation while the MARS does not incorporate cognitive components of psychomotor disturbance (Schrijvers et al., 2007). In the 90s, Parker and his group developed the CORE measure (Parker et al., 1995a,b, Parker and Hadzi-Pavlovic 1996a,b). The CORE is an 18-item, observer-rated measure that comprises three sub-scales: retardation (7 items), agitation (5 items) and non- interactiveness or cognitive impairment (6 items), and with all three summing to generate a total CORE score. The CORE measure was shown in development studies to have high inter-rater reliability, and was validated against a range of biological and Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/jad Journal of Affective Disorders 0165-0327/$ - see front matter & 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jad.2012.03.043 n Corresponding author at: GGZ inGeest, Circuit Ouderen. Valeriuskliniek, Valer- iusplein 9, 1075 BG, Amsterdam. Tel.: þ31 20 788 5659; fax: þ31 20 6727458. E-mail address: d.rhebergen@ggzingeest.nl (D. Rhebergen). Journal of Affective Disorders 142 (2012) 343–346