Some studies point to existence of cognitive deficits in OCD (it seems that these deficits are not comorbid but have the same neurological roots as OCD). Unfortunately I found no studies with positive effects of medication (SSRI etc.) on cognitive deficits/impairment in OCD patients. I found only one study about cognitive-behavioral therapy and improvement of cognitive deficits symptoms in OCD.
Is there any research that indicates medication used to treat OCD (such as SSRIs) can mitigate these cognitive deficits?
Fenger, M. M., Gade, A., Adams, K. H., Hansen, E. S., Bolwig, T. G., & Knudsen, G. M. (2005). Cognitive deficits in obsessive-compulsive disorder on tests of frontal lobe functions. Nordic journal of psychiatry, 59(1), 39-44. PDF
Purcell, R., Maruff, P., Kyrios, M., & Pantelis, C. (1998). Neuropsychological deficits in obsessive-compulsive disorder: a comparison with unipolar depression, panic disorder, and normal controls. Archives of General Psychiatry, 55(5), 415. LINK