The Structured Interview for Hoarding Disorder (SIHD): Development, usage and further validation A.E. Nordsletten a,n , L. Fernández de la Cruz a , A. Pertusa a , A. Reichenberg a,b , S.L. Hatch a , D. Mataix-Cols a a King's College London, Institute of Psychiatry, London, SE5 8AF, UK b Departments of Psychiatry and Preventive Medicine, Seaver Center for Autism Research and Treatment and Friedman Brain Institute, Icahn Medical School at Mount Sinai, New York, NY, USA article info Article history: Received 24 April 2013 Received in revised form 13 June 2013 Accepted 18 June 2013 Available online 24 June 2013 Keywords: Hoarding disorder DSM-5 Diagnosis Assessment Structured interview abstract The Structured Interview for Hoarding Disorder (SIHD) is a semi-structured instrument designed to assist clinicians and trained interviewers with the nuanced diagnosis of hoarding disorder (HD). The manu- script introduces the rationale, development, and design of the SIHD and presents a test of the instrument's inter-rater reliability and convergent/discriminant validity. Ninety-nine individuals with self-reported hoarding behavior, originally recruited as part of a large two-wave epidemiological study, were evaluated in their homes using the SIHD. Diagnoses of HD were determined by consensus, following a best estimate diagnosis procedure. To enable the assessment of inter-rater reliability, a psychiatrist with extensive experience diagnosing HD also independently and blindly reviewed each participant's SIHD. In addition, agreement of SIHD diagnoses with those indicated by other screening instruments for HD and depression were examined. Results indicate “substantial” or “near perfect” inter- rater reliability for all core HD criteria and specifiers. Convergent and discriminant validity were, furthermore, excellent. Overall, the SIHD offers an intuitive, valid, and reliable means of diagnosing HD. The interview also facilitates the assessment of other relevant features, such as risk. We offer recommendations for its use in both research and clinical settings, as well as suggestions for the training of interviewers. & 2013 Published by Elsevier Inc. 1. Introduction The recent inclusion of hoarding disorder (HD) as a new diag- nostic category in DSM-5 (American Psychiatric Association, 2013) has underscored the need for valid and reliable tools tailored to the task of its diagnosis. As highlighted in prior research (e.g., Mataix- Cols et al., 2010), since DSM-III “hoarding” has been framed as a symptom (either of obsessive–compulsive disorder [OCD] or obses- sive–compulsive personality disorder [OCPD]) rather than a syn- drome unto itself. Consistent with this conception, the assessment of hoarding behaviors has, historically, largely taken place in the context of an alternative condition or construct. For example, the Yale–Brown Obsessive Compulsive Scale (Y-BOCS)—widely viewed as the gold standard for assessing OCD symptom severity—prompts the evalua- tion of “hoarding and saving obsessions” and “hoarding and collecting compulsions” in its symptom checklist (Goodman et al., 1989, 1989). While it is true that hoarding can be a symptom of OCD (Pertusa, Frost, & Mataix-Cols, 2010), it is increasingly acknowledged that these items fail to capture the core features of the syndrome (i.e., clutter, distress, interference, etc.), and provide an inadequate assess- ment of the severity of HD (Mataix-Cols et al., 2010). In the wake of seminal work framing “hoarding” as an indepen- dent and definable construct (Frost & Hartl, 1996), the options for assessing hoarding features have expanded. Currently, a number of clinician and self-administered measures exist to assess hoarding features, in particular the severity of aspects such as difficulties discarding, clutter, and distress (for a review see Frost, Steketee, & Tolin, 2012). Some of the most widely used measures include the Hoarding Rating Scale—Interview (HRS-I; Tolin, Fitch, Frost, & Steketee, 2010), the Hoarding Rating Scale—Self Report (HRS-SR; Tolin, Frost, & Steketee, 2010), the Clutter Image Rating (CIR; Frost, Steketee, Tolin, & Renaud, 2008), and the Saving Inventory—Revised (SI-R; Frost, Steketee, & Grisham, 2004). These measures, typically, have empirically derived cut-offs that offer an indication of whether an individual is likely to have clinically-significant hoarding pro- blems. However, while practical—particularly as a means of screen- ing in population-based studies—these tools do not permit a formal diagnosis of HD as they cannot rule out other disorders that may also present with hoarding behavior. Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/jocrd Journal of Obsessive-Compulsive and Related Disorders 2211-3649/$ - see front matter & 2013 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jocrd.2013.06.003 n Corresponding author. Tel.: +44 207 848 5228. E-mail addresses: ashley.keller@kcl.ac.uk, ashley.keller23@gmail.com (A.E. Nordsletten). Journal of Obsessive-Compulsive and Related Disorders 2 (2013) 346–350