The utility of biomarker discovery approaches for the detection of disease mechanisms in psychiatric disorders.

Schizophrenia remains an elusive multifaceted disorder with all evidence of its onset and aetiology pointing to a complex interplay of genetic, nutritional, environmental and developmental factors. Although several molecular and structural abnormalities have been reported for schizophrenia, no diagnostic test or other application of clinical use has yet emerged from this research. The heterogeneity of schizophrenia symptoms and its similarity to other psychiatric disorders, the accessibility of appropriate samples and the complexity of molecular alterations have greatly slowed down research. Biomarker discovery approaches should ultimately facilitate objective diagnosis, allow the identification of at-risk individuals, predict treatment success and revolutionize drug-discovery approaches. For psychiatric disorders, large sample numbers are necessary if disease-intrinsic alterations are to be detected in an environment of high biological variability. Only recent technological advances facilitate the profiling of proteins and metabolites of large sample numbers. These approaches promise to provide interesting insights into disease mechanisms, as they enable capturing the dynamic nature of disease-related alterations. By means of parallel profiling using a multi-omics approach, we aim to disentangle the complex nature of schizophrenia's aetiology. Here, we will outline how this system-based analysis approach can contribute to the discovery of disease mechanisms in schizophrenia and in turn other psychiatric disorders.