We report our activity in the Consultation and Support Service in Toyama（CAST）, a clinical service provided by the collaboration of Toyama Prefectural Mental Health Center and University Hospital of Toyama（UHT）. About 23％ of users diagnosed with at‒risk mental state （ARMS）, during October 2006 until March 2012, transitioned to overt schizophrenia. More than half of the subjects who continued to visit the specialized clinic in UHT were treated with antipsychotic drugs. We encountered a case of schizophrenia in which early treatment with an atypical psychotic drug was effective in normalizing cognitive function and achieving a good social consequence. The ability of mismatch negativity, an event‒related potential, to predict progression to psychosis in subjects with ARMS is discussed. Further efforts should be directed towards improving long‒term outcomes, such as social function, for users of the CAST.