Editorial: Polygenic Risk as a Biomarker for Attention-Deficit/Hyperactivity Disorder

Although the term has been relatively ill defined in psychiatric research, "biomarker" is typically considered a measurable objective characteristic that can predict clinical outcomes such as risk, diagnosis, subgroups, severity, prognosis, and response to treatment.¹ Among several fields of medicine, such as cardiology and oncology, biomarkers have been used to aid clinicians during the various stages of decision-making processes, advancing toward precision medicine and health in which care is tailored based on specific characteristics of individuals. However, that has not been the case for psychiatry until now. Despite the remarkable advancements in our understanding of the etiology and pathophysiology of mental disorders over the past decades, there is no well-validated biomarker incorporated into our clinical practice. We as psychiatrists still find ourselves establishing diagnoses, allocating individuals to treatment, and predicting response without inputs from the accumulated knowledge from neuroscience.