چکیده (انگلیسی):

Background: Obsessive–compulsive disorder (OCD) is associated with impairments in multiple neuropsychological
domains but the findings are rather inconsistent across studies. One potential reason for poor replication
is the confounding influence of medications. There is limited research on neuropsychological
performance in medication-naïve, never treated OCD patients.
Methods: In this study, we assessed 31 medication-naïve, never-treated, DSM-IV OCD patients free of comorbid
major depression and 31 healthy controls individually matched for age, gender and years of education,
with tests of attention, executive function, memory reasoning and visuo-spatial function.
Results: Medication-naïve OCD patients did not significantly differ from healthy controls on most neuropsychological
tests. Patients performed somewhat poorly only on the highest goal hierarchy of the Tower of London
(TOL) test (p=0.001, effect size=0.68).
Conclusions: It is intriguing to find that symptomatic, drug-naïve OCD patients did not significantly differ
from healthy controls on most neuropsychological tests. Our finding of medium effect size on TOL highest
goal hierarchy test suggests that brain regions outside the affective orbitofrontal loop may also be perhaps
involved in OCD. This finding however needs replication because of modest effect size. Future studies should
focus on studying medication-naïve, co-morbidity-free patients and relatives using symptom dimensions for
consistent and robust findings