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Schizophrenia patients with high intelligence: A clinically distinct sub-type of schizophrenia?

  • E. Černis (a1), E. Vassos (a1), G. Brébion (a2), P.J. McKenna (a3), R.M. Murray (a1), A.S. David (a1) and J.H. MacCabe (a1)...

Abstract

Background

Schizophrenia patients are typically found to have low IQ both pre- and post-onset, in comparison to the general population. However, a subgroup of patients displays above average IQ pre-onset. The nature of these patients’ illness and its relationship to typical schizophrenia is not well understood. The current study sought to investigate the symptom profile of high-IQ schizophrenia patients.

Methods

We identified 29 schizophrenia patients of exceptionally high pre-morbid intelligence (mean estimated pre-morbid intelligence quotient (IQ) of 120), of whom around half also showed minimal decline (less than 10 IQ points) from their estimated pre-morbid IQ. We compared their symptom scores (SAPS, SANS, OPCRIT, MADRS, GAF, SAI-E) with a comparison group of schizophrenia patients of typical IQ using multinomial logistic regression.

Results

The patients with very high pre-morbid IQ had significantly lower scores on negative and disorganised symptoms than typical patients (RRR = 0.019; 95% CI = 0.001, 0.675, P = 0.030), and showed better global functioning and insight (RRR = 1.082; 95% CI = 1.020, 1.148; P = 0.009). Those with a minimal post-onset IQ decline also showed higher levels of manic symptoms (RRR = 8.213; 95% CI = 1.042, 64.750, P = 0.046).

Conclusions

These findings provide evidence for the existence of a high-IQ variant of schizophrenia that is associated with markedly fewer negative symptoms than typical schizophrenia, and lends support to the idea of a psychosis spectrum or continuum over boundaried diagnostic categories.

Copyright

Corresponding author

Corresponding author at: University of Oxford Institute of Clinical Psychology Training, Isis Education Centre, Warneford Hospital, Oxford, OX3 7JX. Tel.: +44 779 205 1130. E-mail address:Emma.cernis@hmc.ox.ac.uk (E. Černis).

References

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Keywords

Schizophrenia patients with high intelligence: A clinically distinct sub-type of schizophrenia?

  • E. Černis (a1), E. Vassos (a1), G. Brébion (a2), P.J. McKenna (a3), R.M. Murray (a1), A.S. David (a1) and J.H. MacCabe (a1)...

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Schizophrenia patients with high intelligence: A clinically distinct sub-type of schizophrenia?

  • E. Černis (a1), E. Vassos (a1), G. Brébion (a2), P.J. McKenna (a3), R.M. Murray (a1), A.S. David (a1) and J.H. MacCabe (a1)...
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