This Federal Project Grant award from the National Institute of Mental Health (NIMH), under the Mental Health Research Grants program (CFDA 93.242), is funding a research study entitled "Neurocomputational Mechanisms of Serotonin, Sustained Stress, and Mental Effort Allocation" at Brown University. The $114,899 award supports a 2-year investigation into how serotonin, stress controllability, and cognitive control interact to influence how individuals strategically allocate mental effort when facing sustained stressors. The research leverages behavioral experiments, pharmacological manipulations, and functional neuroimaging to elucidate the neurocomputational mechanisms underlying this process. The findings have the potential to inform interventions for motivational impairments in psychiatric disorders. The award includes a K99 phase focused on model development and a R00 phase for neuroimaging studies.