Impaired test performance yet spared neurocognitive functioning in individuals with obsessive-compulsive disorder:...

Although most studies report neurocognitive deficits in patients with obsessive-compulsive disorder (OCD), important exceptions exist, highlighting the possible role of mediators (e.g., poor motivation). This study investigated neurocognitive functioning and potential influences affecting performance in OCD.

Forty-three participants (13 OCD patients, 30 healthy controls) were assessed using a battery of neurocognitive tests. During the assessment, the examiner completed the Impact on Performance Scale (IPS) which measures variables that may impact neurocognitive performance.

Pooled neurocognitive performance was lower in OCD patients versus healthy controls at a moderate effect size. Patients performed more poorly on the IPS, particularly the Well-Being During Assessment subscale. Performance differences across the two groups were attenuated to a non-significant small-to-medium effect when the IPS was entered as a covariate. A total of 34% of patients showed scores greater than one standard deviation below the mean compared to 9.63% in healthy individuals. Yet, when a conservative impairment criterion (≥2 standard deviations below the mean) was applied, less than 10% of patients displayed deficits.

Neurocognitive impairment in OCD is likely exaggerated. In addition to considering important mediators researchers should report the percentage of participants displaying performance deficits rather than mean group differences alone; the latter obscures the high percentage of patients without impairment and thus may unduly foster stigma in this population.