Computationally-Defined Behaviors in Psychiatry (R21 Clinical Trial Optional) | PAR 23 305

Opportunity Information: Apply for PAR 23 305

Computationally-Defined Behaviors in Psychiatry (R21 Clinical Trial Optional) is an NIH/NIMH grant opportunity (Funding Opportunity Number PAR 23 305; CFDA 93.242) that supports early-stage, exploratory research aimed at making human behavior in mental health more precisely measurable using computational methods. The program is a reissue of an earlier announcement (RFA-MH-21-264) updated to align with NIH data management and sharing (DMS) policy expectations. In practical terms, the FOA is looking for projects that can build and validate well-specified, parameter-rich behavioral tasks or assays, then use computational modeling to quantify the underlying processes that drive performance on those tasks.

The scientific emphasis is on developing "parametrically detailed behavioral assays" across domains of functioning that matter for mental health. That typically means designing tasks where key features can be systematically varied (for example, reward probability, uncertainty, effort cost, learning rate demands, social feedback intensity, or time pressure) so that behavior can be decomposed into interpretable model parameters rather than only broad outcomes like accuracy or reaction time. The FOA is explicitly oriented toward computational approaches, so competitive applications would generally pair a well-designed behavioral paradigm with formal models (for example, reinforcement learning models, Bayesian inference models, drift diffusion models, active inference frameworks, or other generative models) and demonstrate that the model meaningfully captures behavior in a way that can be tested empirically.

A notable constraint of this opportunity is its focus on human behavior and the testing of computational models in healthy participants. The immediate goal is not to run large clinical studies, but to establish robust assays and computational measures under controlled conditions. The "clinical trial optional" designation means an application may include clinical-trial-like elements if they meet NIH definitions, but the core expectation in this FOA is foundational work: developing tasks, establishing reliability and sensitivity, and showing that the computational parameters are well-identified and interpretable in humans. NIMH also signals that it is interested in models that could later be extended to clinical populations, so applicants are encouraged to design measures that are clinically relevant and scalable, even if patient testing is not the centerpiece of the current R21 project.

NIMH places special value on behavioral measures and computational parameters that can be "back-translated" from humans to animals. This is a strategic point: if a computationally defined behavioral signature can be reproduced in animal paradigms, it becomes more useful for preclinical therapeutics development, including target validation and screening of interventions before human trials. As a result, proposals that explicitly consider cross-species task structure, conserved computational constructs (such as learning from prediction errors, sensitivity to volatility, or exploration-exploitation tradeoffs), and methodological features that facilitate animal implementation are likely to align well with the stated priorities. At the same time, the FOA indicates interest in creating models that are not just mathematically elegant but practically useful for psychiatry, meaning the outputs should be interpretable, stable, and plausibly linked to mechanisms that matter for treatment development.

From an administrative standpoint, this is a discretionary grant using the NIH R21 mechanism, which is typically intended for innovative, higher-risk projects that generate strong proof-of-concept data rather than fully mature programs of research. The listed award ceiling is $275,000, and the original closing date shown in the source information is 2023-11-01. The sponsoring agency is the National Institutes of Health, with NIMH as the relevant institute given the mental health focus.

Eligibility is broad and includes many types of U.S. institutions and organizations: state, county, and local governments; special district governments; independent school districts; public and state-controlled universities; private universities; federally recognized tribal governments and other tribal organizations; public housing authorities/Indian housing authorities; nonprofits with or without 501(c)(3) status (excluding higher education institutions in that category); for-profit organizations (other than small businesses); and small businesses. The FOA also highlights additional eligible applicants such as Alaska Native and Native Hawaiian Serving Institutions, Asian American Native American Pacific Islander Serving Institutions (AANAPISIs), Hispanic-serving Institutions, Historically Black Colleges and Universities (HBCUs), Tribally Controlled Colleges and Universities (TCCUs), faith-based or community-based organizations, eligible federal agencies, U.S. territories or possessions, and even non-U.S. entities (foreign organizations) and regional organizations. This wide eligibility reflects an interest in attracting computational, behavioral, and translational expertise from diverse research settings.

Overall, the opportunity is best understood as an NIMH push to strengthen the measurement foundations of psychiatric science by turning complex behaviors into quantitatively defined constructs. The projects NIMH is seeking should produce behavioral tasks and computational parameters that are precise, testable, and potentially portable across species, laying groundwork for future studies that move from healthy human samples into clinical populations and, ultimately, into therapeutics-relevant preclinical pipelines.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Computationally-Defined Behaviors in Psychiatry (R21 Clinical Trial Optional)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.242.
• This funding opportunity was created on 2023-09-19.
• Applicants must submit their applications by 2023-11-01. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $275,000.00 in funding.
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

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