Methods of development

Items for the DOCS were initially written by Jonathan Abramowitz and Brett Deacon and sent to a larger group of experts on OCD and scale development, as well as patients with OCD for feedback regarding the clarity, reading level, and relevance of the items. Following the incorporation of their input, the final product was a self-report instrument consisting of 20 items; five items for each of the four symptom dimensions as described above: (a) contamination, (b) responsibility for harm, injury, or bad luck, (c) unacceptable obsessional thoughts, and (d) symmetry, completeness, and exactness. Hoarding was excluded for the reasons mentioned above.

Within each symptom dimension, five items assess the following parameters of severity over the past month: (a) time occupied by obsessions and compulsions, (b) avoidance behavior, (c) associated distress, (d) functional interference, and (e) difficulty disregarding the obsessions and refraining from the compulsions. Each item is rated on a scale ranging from 0 (no symptom) to 4 (extreme symptoms).

To accommodate the heterogeneity of OCD symptoms, the instructions for each set of five dimension-specific items include a brief description and several broad examples of the types of obsessions and compulsions observed in that dimension. The examples cover the range of symptoms observed within each dimension. Thus, the DOCS assesses the severity of the patient’s own symptoms, rather than pre-defined symptoms as in most self-report OCD scales.

Finally, the DOCS items are worded based on the research-supported idea that obsessions and compulsions are actually universal experiences, occurring in clinical and nonclinical individuals on a continuum of severity. This allows the DOCS to be viable in both clinical and nonclinical populations.

An analysis of the reading level of the DOCS revealed that the DOCS is easily understandable for people aged 13–15 years and above or who read at about a 9th-grade level.