The obsessive-compulsive disorder is characterized by the presence of 1) obsession: ideas, thoughts, impulses or images, felt as intrusive, inappropriate, and out of the patient's control and that cause marked anxiety or distress; and 2) compulsions: repetitive behaviors or mental acts, the goal of which is to prevent or reduce anxiety or distress. The obsessive-compulsive spectrum assessment considers the different clinical expressions of the obsessive-compulsive disorder as belonging to a unique background and integrates the typical symptoms of the disorder, described in the categorical systems, with traits, signs, atypical symptoms, and temperamental and features that constitute a halo around the full-blown disorder, may precede its full evolution, may represent sequelae, or may be the only manifestation of the disorder. This wide range of phenomena may appear alone or interfere with the clinical features and course of other Axis I disorders.

Scoring

Each of the OBS instruments consists of 183 items coded as present or absent for one or more periods of at least 3-5 days through the subject’s lifetime or over the past week or month and collapsed into seven domains.
See algorithm section, below on this page for how to score the instrument.

Psychometric Properties

Dell’Osso L, Cassano GB, Sarno N, Millanfranchi A, Pfanner C, Gemignani A, Maser JD, Shear MK, Grochocinski VJ, Rucci P, Frank E: Validity and reliability of the Structured Clinical Interview for Obsessive-Compulsive Spectrum (SCI-OBS) and of the Structured Clinical Interview for Social Phobia Spectrum (SCI-SHY). Int J Meth Psych Res 9:11-24, 2000.

Dell’Osso L, Rucci P, Cassano GB, Maser JD, Endicott J, Shear MK, Samo N, Saettoni M, Grochocinski VJ, Frank E: Measuring social phobia and obsessive-compulsive disorders: Comparison of interviews and self-report instruments. Compr Psychiatry 43:81-87, 2002.

Note: each items is scored as "0" (NO), "1" (YES). Items from 1 to 23 (first domain) are omitted from the Obs-sr "last week" version and from the Obs-sr "last month" version.
(1) childhood and adolescent experiences	sum of items 1-23
(2) doubt	sum of items 24-36
(3) hypercontrol	sum of items 37-91
(4) use of time	sum of items 92-100
(5) perfectionism	sum of items 101-118
(6) repetition and automation	sum of items 119-130
(7) specific themes	sum of items 131-183
Total score (sum of domains scores) range 0 - 183 Total score for OBS-sr "last month" (sum of domains scores): range 0 - 160 Total score for OBS-sr "last lifetime" (sum of domains scores): range 0 - 183 Threshold for total score for SCI-OBS: 59 Threshold for total score for OBS-sr "lifetime": 59 Threshold for total score for other Obs-sr versions: none determined at this time.