Consensus paper of the WFSBP Task Force on Biological Markers: Criteria for biomarkers and endophenotypes of schizophrenia part I: Neurophysiology

Abstract

The neurophysiological components that have been proposed as biomarkers or as endophenotypes for schizophrenia can be measured through electroencephalography (EEG) and magnetoencephalography (MEG), transcranial magnetic stimulation (TMS), polysomnography (PSG), registration of event-related potentials (ERPs), assessment of smooth pursuit eye movements (SPEM) and antisaccade paradigms. Most of them demonstrate deficits in schizophrenia, show at least moderate stability over time and do not depend on clinical status, which means that they fulfil the criteria as valid endophenotypes for genetic studies. Deficits in cortical inhibition and plasticity measured using non-invasive brain stimulation techniques seem promising markers of outcome and prognosis. However the utility of these markers as biomarkers for predicting conversion to psychosis, response to treatments, or for tracking disease progression needs to be further studied.

Key words::

• endophenotypes
• biomarkers
• schizophrenia
• electrophysiological measures
• diagnosis

Acknowledgements

The authors would like to thank the Presidents of the national societies of biological psychiatry for their helpful comments.

Statements of Interest

Alkomiet Hasan has been invited to scientific meetings by Lundbeck, Janssen-Cilag, and Pfizer, and he received paid speakership by Desitin, Otsuka and the Federal Union of German Associations of Pharmacists. He was member of the Roche Advisory Board. In the last 5 years, Zafiris J. Daskalakis (ZJD) received research and equipment in-kind support for an investigator-initiated study through Brainsway Inc. ZJD has also served on the advisory board for Hoffmann-La Roche Limited and Merck and received speaker support from Sepracor and Eli Lilly. This work was supported by the Ontario Mental Health Foundation (OMHF), the Canadian Institutes of Health Research (CIHR), the Brain and Behaviour Research Foundation and the Temerty Family and Grant Family and through the Centre for Addiction and Mental Health (CAMH) Foundation and the Campbell Institute, A.Wichniak has been member of the Lundbeck and Janssen-Cilag advisory boards, has been invited to scientific meetings by Angelini, Lundbeck and Servier, has received paid speakership by Angelini, Janssen-Cilag, Lundbeck and Servier, A. Schmitt was an honorary speaker for TAD Pharma and Roche and has been a member of advisory boards for Roche. F. Thibaut was invited to a scientific meeting by Takeda, she is WHO expert for drug dependence, she received a grant from Servier. P. Falkai has been an honorary speaker for Janssen-Cilag, Astra-Zeneca, Eli Lilly, Bristol Myers-Squibb, Lundbeck, Pfizer, Bayer Vital, SmithKline Beecham, Wyeth, and Essex. During the past 5 years, but not presently, Peter Falkai has been a member of the advisory boards of Janssen-Cilag, AstraZeneca, Eli Lilly, and Lundbeck.