Using genetic, cognitive and multi-modal neuroimaging data to identify ultra-high-risk and first-episode psychosis at the individual level. Issue 12 (December 2013)

• Record Type: Journal Article
• Authors: Pettersson-Yeo, W.; Benetti, S.; Marquand, A. F.; Dell'Acqua, F.; Williams, S. C. R.; Allen, P.; Prata, D.; McGuire, P.; Mechelli, A.
• Is Part Of: Psychological medicine. Volume 43:Issue 12(2013)
• Page Start: 2547
• Page End: 2562
• Publication Date: 2013-12
• Subjects: Psychiatry -- Periodicals; Medicine and psychology -- Periodicals; Clinical psychology -- Periodicals; 616.89
• DOI: 10.1017/S003329171300024X
• Languages: English
• ISSNs: 0033-2917

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec id="sec_a1"> <title>Background</title> <p>Group-level results suggest that relative to healthy controls (HCs), ultra-high-risk (UHR) and first-episode psychosis (FEP) subjects show alterations in neuroanatomy, neurofunction and cognition that may be mediated genetically. It is unclear, however, whether these groups can be differentiated at single-subject level, for instance using the machine learning analysis support vector machine (SVM). Here, we used a multimodal approach to examine the ability of structural magnetic resonance imaging (sMRI), functional MRI (fMRI), diffusion tensor neuroimaging (DTI), genetic and cognitive data to differentiate between UHR, FEP and HC subjects at the single-subject level using SVM.</p> </sec> <sec id="sec_a2" sec-type="methods"> <title>Method</title> <p>Three age- and gender-matched SVM paired comparison groups were created comprising 19, 19 and 15 subject pairs for FEP <italic>versus</italic> HC, UHR <italic>versus</italic> HC and FEP <italic>versus</italic> UHR, respectively. Genetic, sMRI, DTI, fMRI and cognitive data were obtained for each participant and the ability of each to discriminate subjects at the individual level in conjunction with SVM was tested.</p> </sec> <sec id="sec_a3" sec-type="results"> <title>Results</title> <p>Successful classification accuracies (<italic>p</italic> < 0.05) comprised FEP <italic>versus</italic> HC (genotype, 67.86%; DTI, 65.79%; fMRI, 65.79% and 68.42%; cognitive data, 73.69%), UHR <italic>versus</italic> HC (sMRI, 68.42%; DTI, 65.79%), and FEP <italic>versus</italic> UHR (sMRI, 76.67%; fMRI, 73.33%; cognitive data, 66.67%).</p> </sec> <sec id="sec_a4" sec-type="conclusion"> <title>Conclusions</title> <p>The results suggest that FEP subjects are identifiable at the individual level using a range of biological and cognitive measures. Comparatively, only sMRI and DTI allowed discrimination of UHR from HC subjects. For the first time FEP and UHR subjects have been shown to be directly differentiable at the single-subject level using cognitive, sMRI and fMRI data. Preliminarily, the results support clinical development of SVM to help inform identification of FEP and UHR subjects, though future work is needed to provide enhanced levels of accuracy.</p> </sec> </abstract>