Brain correlates of verbal fluency in subthreshold psychosis assessed by functional near-infrared spectroscopy.
The prevalence of subthreshold psychotic symptoms in the general population has gained increasing interest as a possible precursor of psychotic disorders. The goal of the present study was to evaluate whether neurobiological features of subthreshold psychotic symptoms can be detected using verbal fluency tasks and functional near-infrared spectroscopy (fNIRS). A large data set was obtained from the Zurich Program for Sustainable Development of Mental Health Services (ZInEP). Based on the SCL-90-R subscales 'Paranoid Ideation' and 'Psychoticism' a total sample of 188 subjects was assigned to four groups with different levels of subthreshold psychotic symptoms. All subjects completed a phonemic and semantic verbal fluency task while fNIRS was recorded over the prefrontal and temporal cortices. Results revealed larger hemodynamic (oxy-hemoglobin) responses to the phonemic and semantic conditions compared to the control condition over prefrontal and temporal cortices. Subjects with high subthreshold psychotic symptoms exhibited significantly reduced hemodynamic responses in both conditions compared to the control group. Further, connectivity between prefrontal and temporal cortices revealed significantly weaker patterns in subjects with high subthreshold psychotic symptoms compared to the control group, possibly indicating less incisive network connections associated with subthreshold psychotic symptoms. The present findings provide evidence that subthreshold forms of psychotic symptoms are associated with reduced hemodynamic responses and connectivity in prefrontal and temporal cortices during verbal fluency that can be identified using fNIRS.
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland. Electronic address: lisa.holper@puk.zh.ch.
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Holper
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland.
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Aleksandrowicz
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland.
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M
Müller
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland.
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Ajdacic-Gross
The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland; Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Switzerland.
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H
Haker
Department of Psychiatry Psychotherapy, University of Tübingen, Germany; LEAD Graduate School, University of Tübingen, Germany.
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Fallgatter
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland.
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Hagenmuller
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland; Institute of Psychiatry, Laboratory of Neuroscience, LIM27, University of Sao Paulo, Brazil.
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Rössler
Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Switzerland; The Zurich Program for Sustainable Development of Mental Health Services, University Hospital of Psychiatry Zurich, Switzerland.
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Kawohl
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000378:metabolism*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism*; D010258:Paranoid Behavior / Q000209:etiology; D062706:Prodromal Symptoms; D011618:Psychotic Disorders / Q000150:complications* / Q000453:epidemiology; D019265:Spectroscopy, Near-Infrared; D013064:Speech Disorders / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D055815:Young Adult
D010108:Oxyhemoglobins
Epidemiology; Paranoid Ideation; Psychoticism; Subthreshold psychotic symptoms; fNIRS