Neuropsychological performance across symptom dimensions of obsessive-compulsive disorder: a comment on the state and critical review of the literature.

: Obsessive-compulsive disorder (OCD) is a heterogeneous disorder, with multiple symptom presentations. Delineating the neuropsychological characteristics associated with previously identified symptom clusters may therefore be useful in assisting to better define symptom subtypes of OCD.: This review summarizes the existing literature on the assessment of neuropsychological performance in symptom-based dimensions of OCD. Results of 23 studies are described and the methodological issues and challenges present in this body of literature are discussed.: The current state of the literature precludes a meaningful meta-analysis of cognitive dysfunction across the breadth of symptom dimensions of OCD. This is due primarily to significant methodological differences observed between studies, both in terms of neuropsychological measures and symptom subtyping methods employed, and any resulting meta-analytic results would be biased by varying quality of evidence. Future studies addressing these limitations should include more consistent neuropsychology measures and methods of classifying OCD symptoms with the aim of reproducing the results of previous research to identify more concrete patterns of neuropsychological performance across dimensions; best practices and alternative approaches are discussed.