The National Institute of Mental Health Data Archive (NDA) is a collection of research data repositories including the NIMH Data Archive (NDA), the Research Domain Criteria Database (RDoCdb), the National Database for Clinical Trials related to Mental Illness (NDCT), and the NIH Pediatric MRI Repository (PedsMRI). The NDA infrastructure was established initially to support autism research, but has grown into an informatics platform that facilitates data sharing across all of mental health and other research communities.

The NIH and the NIMH seek to encourage the use of these resources to achieve accelerated scientific progress. In order to take full advantage of such resources and maximize their research value, it is important that data be made available, on appropriate terms and conditions, to the largest possible number of qualified investigators in a timely manner.