Unfortunately, developing medicines to treat mental illness has some of the lowest probabilities of success. This is due in large part to the inherent scientific challenges and complexities that come with developing medicines to treat these illnesses, including a limited understanding of the brain and the neurochemical pathways involved in these illnesses. Though the field of neuroscience has made advancements in recent years, there remains a significant gap in the larger understanding of how mental illnesses develop in the first place. This, combined with the extremely diverse nature of the diseases themselves — which often manifest differently in different people — have made it difficult to identify biomarkers that can aid in diagnosis, treatment and the development of medicines to treat these illnesses.