Circadian rhythms in metabolism and mental health: a reciprocal regulatory network with implications for metabolic and neuropsychiatric disorders

Circadian rhythms orchestrate metabolism and brain function, aligning internal physiological processes with the 24-hour day–night cycle. Growing evidence highlights a reciprocal relationship between circadian regulation, metabolism, and neurobiological processes. Circadian disruption impairs glucose and lipid homeostasis, alters neurotransmitter and endocrine signalling, and triggers stress response, forming a feedback loop that impacts metabolism and brain function. These disturbances are implicated in many conditions, such as obesity, diabetes, depression, and bipolar disorder. This review examines recent advances in the interplay between circadian regulation, metabolism, and mental health, emphasising shared molecular mechanisms and their role in disease progression. Understanding these connections may ultimately inform therapeutic strategies that integrate circadian-based approaches to improve treatments for metabolic and psychiatric disorders.