The search for imaging biomarkers in psychiatric disorders.

The field of medicine is moving toward the use of biomarkers for the optimization of individualized care. This is a particular challenge for the field of psychiatry, in which diagnosis is based on a descriptive collection of behaviors without the availability of any objective test to stratify patients. Neuroimaging techniques such as molecular imaging with positron-emission tomography (PET) or structural and functional magnetic resonance imaging (MRI) provide an opportunity to bring psychiatry from an era of subjective descriptive classification into objective and tangible brain-based measures. Here we provide steps toward the development of robust, reliable and valid biomarkers. The success of such development is crucial because it will enable the field of psychiatry to move forward into the era of modern medicine.