An Overview on the Search for Schizophrenia Biomarkers.

Schizophrenia is a severe psychiatric disorder with a complex presentation comprising positive symptoms (e.g.: hallucinations and delusions), negative symptoms (e.g.: social withdrawal, blunted affect) and pervasive cognitive deficits that have been associated with functional decline. The pathophysiology of the disorder is equally complex, with abnormalities known to occur in the molecular, cellular, neurophysiological, and neuroanatomical domains. Despite significant progress in the comprehension of the various manifestations of schizophrenia, the full picture of its etiology remains unknown. As a result, currently available pharmacological treatments have limited efficacy and little has improved since the discovery of the first antipsychotics back in the 1950s. In addition, these medications have significant adverse effects. Differently from other medical areas, the diagnosis of schizophrenia is essentially clinical and dependent on subjective elements. In an attempt to change this, efforts have been directed to find biomarkers of the disorder that could improve diagnostic accuracy and validity, predict treatment response, enable the early identification of individuals at risk of developing schizophrenia and indicate new targets for the development of drugs with better selective, safety, and efficacy profiles. In this article we describe the main potential schizophrenia markers currently under study and suggest avenues for future research in the field. KEY POINTS: - No reliable markers exist for schizophrenia to date. - The identification of schizophrenia markers could increase diagnostic accuracy and treatment efficacy. - The main research lines in the current search for biomarkers are described.