Neuropsychological differences between obsessive-compulsive washers and checkers: a systematic review and meta-analysis.

Inconsistent results in neuropsychological research of obsessive-compulsive disorder (OCD) may be the result of the heterogeneous nature of OCD symptoms. The most frequently investigated symptoms are contamination/cleaning and doubt/checking. The aim of this review was to determine whether OCD washers and checkers differ in their neuropsychological performance.