The National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH), has reissued its funding opportunity for the "Exploratory Clinical Neuroscience Research on Substance Use Disorders (SUD)" (R61/R33). This Notice of Funding Opportunity (NOFO) aims to support innovative, exploratory, and developmental research that investigates the neurobiological mechanisms underlying SUD, including studies on fundamental neural circuitry and behaviors relevant to substance use. Applicants have the option to propose clinical trials in this research, making it suitable for projects that involve human participants but are not restricted to clinical trials.

This phased award mechanism (R61/R33) funds two project stages: the R61 phase (up to 2 years), which supports planning and pilot research, and the R33 phase (up to 3 years), which extends the study based on successful completion of pre-established milestones in the R61 phase. Approximately 50% of projects funded in the R61 phase are expected to transition to the R33 phase, contingent upon meeting milestones. The research must be high-risk, high-reward, focusing on novel areas or methods, with the potential for breakthroughs in SUD research. NIDA encourages applications that explore topics such as neurobiological risk factors for drug addiction, individual differences in neural circuits, and the study of cognitive and behavioral processes related to substance use.

Projects may also examine variables such as the transition from drug use to addiction, neurobiological signatures of SUD, and computational models that map brain networks associated with substance use. Researchers are encouraged to investigate not only SUD but also its interaction with co-occurring psychiatric disorders, or transdiagnostic factors shared by other conditions, such as HIV/AIDS.

The funding offers up to $500,000 in direct costs for the R61 phase, with no budget limit for the R33 phase. However, applicants requesting more than $500,000 in direct costs for the R33 phase in any year must consult NIDA staff at least six weeks before submission. Institutions of higher education, non-profits, for-profit organizations, and international entities are eligible to apply. NIDA also encourages applications from minority-serving institutions and organizations supporting underrepresented groups.

The application process requires the submission of both a detailed research plan and a set of quantitative milestones for the R61 phase, which will be reviewed for feasibility and impact. The transition to the R33 phase is contingent upon successful milestone completion. Applicants are strongly encouraged to contact NIDA program staff to ensure that their proposals align with NOFO guidelines.

Applications may be submitted through NIH ASSIST, Grants.gov, or institutional submission systems. Key deadlines are set throughout the year, with the next due date being March 13, 2025. The NOFO expires on May 8, 2026. Researchers interested in submitting an application should review NIH policies on data management and clinical trial reporting and adhere to all submission guidelines outlined in the SF424 (R&R) Application Guide.