The National Institute of Mental Health (NIMH) is the lead federal agency for research on mental disorders. NIMH is one of the 27 Institutes and Centers that make up the National Institutes of Health (NIH), the largest biomedical research agency in the world. NIH is part of the U.S. Department of Health and Human Services (HHS).

NIMH funds research by scientists across the country as well as in NIMH studies in the internal research program. Through its extramural program, NIMH supports more than 2,000 research grants and contracts at universities and other institutions across the country and overseas. Investigators propose projects themselves through grant applications and must apply for renewals at intervals in order to receive continued funding.