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. 2014 Aug:10:45-50.
doi: 10.1016/j.ajp.2014.03.010. Epub 2014 May 9.

Clinical correlates of parametric digit-symbol substitution test in schizophrenia

Anekal C Amaresha  1 , Vijay Danivas  1 , Venkataram Shivakumar  1 , Sri Mahavir Agarwal  1 , Sunil V Kalmady  1 , Janardhanan C Narayanaswamy  1 , Ganesan Venkatasubramanian  2
Affiliations

Clinical correlates of parametric digit-symbol substitution test in schizophrenia

Anekal C Amaresha et al. Asian J Psychiatr. 2014 Aug.

Abstract

Processing speed deficit, ascertained by digit-symbol substitution test (DSST), is considered as a fundamental impairment in schizophrenia. Clinical correlates of processing speed abnormalities, especially using the parametric version of DSST is yet to be evaluated comprehensively. In this study, we examined schizophrenia patients (N=66) and demographically matched healthy controls (N=72) using computer-administered parametric DSST (pDSST) with fixed (pDSSTF) as well as random (pDSSTR) conditions and analysed the relationship between pDSST performance and clinical symptoms. Psychopathology was assessed using Scale for Assessment of Positive Symptoms (SAPS)/Negative Symptoms (SANS) with good inter-rater reliability. In comparison with healthy controls, patients demonstrated significantly lesser number of correct responses (CN) in pDSSTF (t=8.0; p<0.001) and pDSSTR (t=7.8; p<0.001) as well as significantly prolonged reaction time in pDSSTF (t=7.1; p<0.001) and pDSSTR (t=7.0; p<0.001). The difference in CN between pDSSTF and pDSSTR [ΔCN] was significantly lesser in patients than healthy controls (t=2.61; p=0.01). The pDSST reaction time had significant positive correlation with negative syndrome scores as well as bizarre behaviour score. Significantly greater processing speed deficits in pDSST suggest potential relational memory/visual scanning abnormalities in schizophrenia. Furthermore, pDSST deficits demonstrated a significant association with the psychopathology, especially with the various negative symptoms and bizarre behaviour.

Keywords: Cognitive deficits; Negative symptoms; Processing speed; Schizophrenia.

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Figures

Fig. 1
Fig. 1
shows representative test stimuli of parametric digit-symbol substitution.
Fig. 2
Fig. 2
Comparative profile of difference in correct responses (fixed minus random conditions) during the parametric DSST: schizophrenia patients (N = 66) vs. healthy controls (N = 72).
Fig. 3
Fig. 3
Significant positive correlation between reaction time during parametric DSST and negative syndrome score in schizophrenia patients (N = 66).
See this image and copyright information in PMC

References

    1. Achim A.M., Lepage M. Is associative recognition more impaired than item recognition memory in schizophrenia? A meta-analysis. Brain Cogn. 2003;53:121–124. - PubMed
    1. Aksaray G., Oflu S., Kaptanoglu C., Bal C. Neurocognitive deficits and quality of life in outpatients with schizophrenia. Prog. Neuropsychopharmacol. Biol. Psychiatry. 2002;26:1217–1219. - PubMed
    1. Amado I., Olie J.P. Effects of disorganization on choice reaction time and visual orientation in untreated schizophrenics. Dialogues Clin. Neurosci. 2006;8:53–58. - PMC - PubMed
    1. Andreasen N.C. University of Iowa; Iowa City, IA: 1983. The Scale for the Assessment of Negative Symptoms (SANS)
    1. Andreasen N.C. University of Iowa; Iowa City, IA: 1984. The Scale for the Assessment of Positive Symptoms (SAPS)

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