Longitudinal study of symptoms and cognitive function in chronic schizophrenia

Hughes, Catherine; Kumari, Veena; Soni, William; Das, Mrigendra; Binneman, Brendon; Drozd, Sonia; O'Neil, Shaun; Mathew, Vallakalil; Sharma, Tonmoy

« Previous Next »Schizophrenia Research
Volume 59, Issue 2 , Pages 137-146, 1 February 2003

Longitudinal study of symptoms and cognitive function in chronic schizophrenia

Catherine Hughes
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
Veena Kumari
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
- Department of Psychology, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
William Soni
- Clinical Neuroscience Research Centre, Stonehouse Hospital, Cotton Lane, Dartford, Kent DA2 6AU, UK
Mrigendra Das
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
Brendon Binneman
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
Sonia Drozd
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
Shaun O'Neil
- Section of Cognitive Psychopharmacology, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
Vallakalil Mathew
- Clinical Neuroscience Research Centre, Stonehouse Hospital, Cotton Lane, Dartford, Kent DA2 6AU, UK
Tonmoy Sharma
- Corresponding author. Tel.: +44-1322-622104; fax: +44-1322-622110
- Clinical Neuroscience Research Centre, Stonehouse Hospital, Cotton Lane, Dartford, Kent DA2 6AU, UK

Received 3 March 2001; received in revised form 14 November 2001; accepted 14 November 2001.

Abstract

There is conflicting evidence of a relationship between changes in symptoms and cognitive functioning in schizophrenia. This study investigated longitudinal changes in psychopathology and cognitive functioning in chronic schizophrenia utilising three different dimensional models of symptomatology. Sixty-two patients diagnosed with DSM-IV schizophrenia or schizoaffective disorder were examined on two occasions over a period of 6 months for symptom improvement, measured by Positive and Negative Syndrome Scale (PANSS) [Kay et al., Schizophr. Bull. 13 (1987) 261]. Participants also completed a comprehensive battery of neuropsychological tasks designed to assess attention, verbal and non-verbal memory, psychomotor processing and executive/frontal functioning on both occasions. Twenty-five control subjects were assessed for comparison purposes. Severity of negative symptoms predicted poor neuropsychological performance on IQ, verbal fluency and memory measures at occasion one. However, using regression analyses, significant improvements in symptom ratings over time using two-, three- or five-dimensional models did not predict improvements in any aspect of cognitive functioning measured, except motor speed. The results do not suggest a causal relationship between the course of symptoms and neuropsychological functioning in chronic schizophrenia.

Keywords: Cognitive impairment, Negative symptoms, Chronic schizophrenia