Obsessive-compulsive disorder and the impulsivity-compulsivity disorder spectrum: A review of research

This paper reviews research on the association between obsessive-compulsive disorder (OCD) and obsessive-compulsive spectrum disorders (OCSDs). Since a unidimensional impulsivity-compulsivity dimension has been proposed to classify OCSDs (Bartz and Hollander, 2006), consisting of "compulsive" or anxiety-driven disorders such as OCD on one end of the spectrum and impulse-control disorders (ICDs) on the other end, research on relationships between OCD and various OCSDs has been reviewed to determine if data exist to support a continuous impulsive-compulsive disorder spectrum. Disorders are compared with respect to the following criteria: 1) degrees of co-occurring behaviors and symptomology, 2) phenotypic associations (including comorbidity and familial linkages), 3) neurological and brain-based similarities, and 4), identified response patterns to psychological and medical treatments. In general, there is limited support for a unified impulsivity-compulsivity dimension that includes OCD as a central disorder. However, considerably stronger evidence exists for a narrower cluster of anxiety-driven OCSDs that are characterized by obsessive-compulsive features and body image/sensitization obsessions (e.g., OCD, body dysmorphic disorder, hypochondriasis).