Diagnosis is fundamental to clinical practice. Patients look to us to make sense of their problems, give them a name, unlock access to services, organize treatment, and lead to better outcomes. Gibbons et al.¹ developed and validated a computer-assisted diagnostic interview that covers common clinical problems. Using two large samples, they statistically calibrated a pool of 1,060 items so that adaptive testing can yield a precise estimate of problem severity. The method is akin to the way that college admissions tests are being shortened than the older “skip out” method of discontinuing sections of an interview based on gate-keeping questions. Gibbons et al.¹ take several extra steps to build a more complete foundation for clinical use, including validation in a second, different sample, as well as investigating retest reliability. The product is a tool that could enhance mental health care, and have a transformative effect in many systems of care and regions of the world.