Cognitive Diagnostics segmentation by application maps demand to the clinical settings where cognition is formally evaluated. Neuropsychology dominates volume because every stroke, traumatic-brain-injury or dementia work-up now requires standardized test batteries that quantify memory, attention and executive decline; reimbursement codes in the U.S. alone generated over USD 420 million in 2023 service revenue. Psychiatry is the fastest-growing slice as payors accept digital phenotyping tools for ADHD, schizophrenia and treatment-resistant depression, pushing five-year CAGR above 14%. Academic & research contracts feed longitudinal normative datasets, while corporate wellness budgets convert 10-15 minute gamified assays into employee-screening subscriptions, a segment still sub-5% but attractive for platform vendors seeking recurring SaaS income rather than one-off test sales. Each vertical commands distinct price points, regulatory pathways and evidence requirements, so suppliers typically modularize battery length and normative references to fit the purchasing logic of hospitals, CROs, schools or HR departments.