Department of Psychiatry, NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, London
Department of Psychiatry, NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London and Department of Psychology, University of Westminster London
Department of Psychiatry, NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, London
Community Health Sciences, Queens Medical Centre, Institute of Clinical Research, University of Nottingham, Nottingham
Academic Unit of Psychiatry, University of Bristol, Bristol
Department of Psychiatry, University of Cambridge, Cambridge
Department of Psychiatry, NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, London, UK
Correspondence: Eugenia Kravariti, PhD, Department of Psychiatry, Box 58, NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, Kings College London, De Crespigny Park, London SE5 8AF, UK. Email: e.kravariti{at}iop.kcl.ac.uk
Background
Identifying neurocognitive subtypes in schizophrenia may help establish neurobiologically meaningful subtypes of the disorder, but is frequently confounded by differences in intellectual function between individuals with schizophrenia and controls.
Aims
To examine neuropsychological performance in individuals with epidemiologically based, first-onset schizophrenia and intellectually matched controls.
Method
Using standard IQ and reading tests, we examined the proportions of 101 people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder and 317 community controls, falling into three a priori defined intellectual categories: stable good, deteriorated poor and stable poor. Neuropsychological function was compared between intellectually matched participants with schizophrenia and control subgroups.
Results
Multiple deficits in executive function, processing speed and verbal memory, but not visual/spatial perception/memory, were detected in all participant groups with schizophrenia compared with controls. The average effect size across the affected domains ranged from small to medium to large in the stable good, deteriorated poor and stable poor subgroups of participants with schizophrenia, respectively.
Conclusions
Compared with intellectually matched controls, people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder show multiple deficits in executive function, processing speed and verbal memory.
Related articles in BJP: