The National Institutes of Health (NIH), through the National Institute of Mental Health (NIMH), is offering funding for Research Project Grants (R01) aimed at developing screening assays for drug candidates treating mental illnesses. The initiative focuses on validating "hits," compounds that exhibit desired biological activity in initial screenings and confirmed in follow-up assays. The funding opportunity includes three research stages: assay development, primary screening implementation, and hit validation. Applications must address the project's significance and innovation and delineate plans for research rigor, feasibility, and organizational capacity. Eligible entities include higher education institutions, nonprofits, for-profit organizations, and governmental bodies, with a maximum project period of five years. The funding's purpose is to stimulate research into novel therapeutics for psychiatric conditions such as depression, schizophrenia, and PTSD. Applicants are encouraged to align their proposals with NIMH priorities and include appropriate data management and sharing plans post-approval. The application submission process involves adherence to the NIH application guide, with strict compliance to improve the likelihood of funding success.