Grey Matter Neurosciences named treatment-resistant depression as its first clinical focus and launched a patient registry to support recruitment. The Toronto company is commercializing focused ultrasound technology developed over the past decade at Sunnybrook Research Institute, designed to reach deep brain structures without surgery, incisions, or shaving the head. Its pilot study, targeting seniors and adults with treatment-resistant depression, is expected to begin in early 2027. The company frames depression as the first step toward a broader platform for brain disorders.