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The neuropsychology of the schizo-obsessive subtype of schizophrenia: a new analysis

Published online by Cambridge University Press:  12 October 2009

D. D. Patel ,
K. R. Laws ,
A. Padhi ,
J. M. Farrow ,
K. Mukhopadhaya ,
R. Krishnaiah  and
N. A. Fineberg
D. D. Patel
Affiliation:
School of Psychology, University of Hertfordshire, UK
K. R. Laws*
Affiliation:
School of Psychology, University of Hertfordshire, UK
A. Padhi
Affiliation:
National OCDs Specialist Service, Herts. Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, Welwyn Garden City, Herts, UK
J. M. Farrow
Affiliation:
National OCDs Specialist Service, Herts. Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, Welwyn Garden City, Herts, UK
K. Mukhopadhaya
Affiliation:
National OCDs Specialist Service, Herts. Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, Welwyn Garden City, Herts, UK
R. Krishnaiah
Affiliation:
National OCDs Specialist Service, Herts. Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, Welwyn Garden City, Herts, UK
N. A. Fineberg
Affiliation:
Postgraduate Medical School, University of Hertfordshire, UK National OCDs Specialist Service, Herts. Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, Welwyn Garden City, Herts, UK
*
*Address for correspondence: Professor K. R. Laws, School of Psychology, University of Hertfordshire, Hatfield AL10 9AB, UK. (Email: k.laws@herts.ac.uk)
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Abstract

Background

Interest in the neuro-cognitive profile of patients with schizophrenia and co-morbid obsessive compulsive disorder (schizo-OCD) is rising in response to reports of high co-morbidity rates. Whereas schizophrenia has been associated with global impairment in a wide range of neuro-cognitive domains, OCD is associated with specific deficits featuring impaired performance on tasks of motor and cognitive inhibition involving frontostriatal neuro-circuitry.

Method

We compared cognitive function using the CANTAB battery in patients with schizo-OCD (n=12) and a schizophrenia group without OCD symptoms (n=16). The groups were matched for IQ, gender, age, medication, and duration of illness.

Results

The schizo-OCD patients made significantly more errors on a task of attentional set-shifting (ID-ED set-shift task). By contrast, no significant differences emerged on the Stockings of Cambridge task, the Cambridge Gamble Task or the Affective Go/NoGo tasks. No correlation emerged between ID-ED performance and severity of schizophrenia, OCD or depressive symptoms, consistent with neurocognitive impairment holding trait rather than state-marker status. Schizo-obsessives also exhibited a trend toward more motor tics emphasizing a neurological contribution to the disorder.

Conclusion

Our findings reveal a more severe attentional set-shifting deficit and neurological abnormality that may be fundamental to the neuro-cognitive profile of schizo-OCD. The clinical implications of these impairments merit further exploration in larger studies.

Keywords

Endophenotypefrontal lobesobsessive-compulsiveset-shifting
Type
Original Articles
Information
Psychological Medicine , Volume 40 , Issue 6 , June 2010 , pp. 921 - 933
Copyright
Copyright © Cambridge University Press 2009

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