The National Institute of Mental Health (NIMH) is  a part of the U.S. Federal government's research organization specializing in mental health. It is a portion of the 27 organizations of the National Institutes of Health. The NIH is a part of the Department of Health and Human Services.

The mission of the NIMH is to reduce the occurrence of mental and behavioral illness through research on the mind, brain and behavior. Formally established in 1949, in Bethesda, Maryland it is particularly known for its research of genetics, neuroscience and psychiatric medication clinical trials.

In the 1960's, NIMH campaigned on special mental health problems as a response to President Lyndon Johnson's objective to use scientific research to better social problems. Centers were established for research to be done on schizophrenia, child and family mental health, and suicide as well as alcohol abuse. There were also researches on crime, minority 's mental health, urban problems and victims of rape, aging and natural disasters.

In the 1970's the National Institute of Drug Abuse and the National Institute on Alcohol abuse were both established within the NIMH. The President's Commission on Mental Health recommendations helped to form The Mental Health Systems Act. It was developed to give improved services to those with mental disorders.

The 1990's brought  about a variety  of increasing public participation in its planning processes. They expanded public education programs.

The research conducted and supported by the NIMH offers hope to those who suffer from mental illness. Many years of research with animals and human subjects has expanded our knowledge of the brain and our ability to diagnose, treat and prevent brain disorders and mental illness through professionals. The National Institute of Mental Health provides research on the brain, body and mind to combat the existence of mental health illnesses and behavioral disorders in the United States.