Comparative Analysis of Cognitive Function in Schizophrenia with and without Obsessive Compulsive Disorder.
OBJECTIVE
We investigated the neurocognitive deficits in schizophrenic patients with and without obsessive-compulsive disorder (OCD).


METHODS
We grouped 27 patients as either obsessive-compulsive or non-obsessive-compulsive based on the presence of OCD. The two groups completed the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Positive and Negative Symptom Scale (PANSS), and Hamilton Depression Scale. The intelligence quotient (IQ) was tested using the Korean Wechsler Adult Intelligence Scale. The memory quotient (MQ) was tested using the Korean-Auditory Verbal Learning and Korean-Complex Figure Test. The executive intelligence quotient (EIQ) was determined using the Kims executive intelligence test (EXIT).


RESULTS
Ten of the 27 patients had OCD. The compulsion score of Y-BOCS was positively correlated with positive symptoms, negative symptoms, and the total scores of PANSS. The OCD-schizophrenia patients had higher IQs. No difference was found in MQ. Although the EIQ did not differ between the two groups, the OCD-schizophrenia patients performed better at the Stroop-interference and verbal fluency tests, which was highly dependent on executive function.


CONCLUSIONS
Our findings suggest that OCD may have a protective effect on some cognitive function, at least in relatively early stage of illness. Moreover, based on clinical, neurocognitive features, schizophrenia with OCD could be considered as a distinct subtype of schizophrenia.
Lee
Myung-Ji
MJ
Department of Psychiatry, Inha University College of Medicine, Incheon, Korea.
Shin
Yong-Bum
YB
Sunwoo
Young-Kyung
YK
Jung
Seung-Ho
SH
Kim
Won-Hyoung
WH
Kang
Min-Hee
MH
Lee
Jeong-Seop
JS
Bae
Jae-Nam
JN
Kim
Chul-Eung
CE