Founded in 2018 and based in Boston, Massachusetts, CompanionMx uses active monitoring of voice and passive monitoring of smartphone metadata to continuously generate acoustic and behavioral biomarkers that predict core symptoms of mood and anxiety disorders. The company's platform, called Companion, offers clinicians an objective view of a patient's behavioral health state, enabling better care. Clinically validated at Harvard Medical School teaching hospitals and multiple Veterans Affairs clinics, the software has been used by over 1,500 patients and numerous behavioral health care clinicians and researchers.