Facilitating Thought Progression: A Neurocognitive Framework Linking Thought Dynamics and Mood Disorders

Mood and thought are tightly coupled, but the mechanisms that link them are not understood. This link is particularly important when considering mood disorders such as depression. We propose the facilitating thought progression (FTP) framework, which characterizes depression as a disorder of thought dynamics, encompassing both the temporal evolution and semantic expanse of mental activity. Five parameters jointly determine the fluency of thought progression: breadth, speed, flexibility, novelty, and scope. Diminished progression, reflected by repetitive, slow, and narrowed thinking, is associated with excessive inhibition, reduced plasticity, blunted reward signaling, and overly deep attractor dynamics. Conversely, interventions that enhance associative expansion, cognitive flexibility, and exploratory behavior restore adaptive brain dynamics. FTP reframes depression as a disorder of cognitive flow rather than content and provides a mechanistic, testable model for translational research.