Each month our editorial team sifts through hundreds of papers and curates notable findings—for practitioners and informed readers who want to stay current with the evidence. Subscribe to the monthly Research Digest for expert analysis and concise summaries of key papers.
Sleep problems are very common in bipolar disorder, which affects about 1% of people in their lifetime. Research suggests these problems relate to disruptions in both the body’s internal clock (circadian system, “process C”) and the sleep–wake drive (homeostasis, “process S”), though this is not proven to be the single…
This review looked at studies in animals and people about how stress and the balance system (the vestibular system) affect each other. In many animal experiments, vestibular damage or stimulation turns on the body's stress system (the HPA axis) and short-term stress hormones help brain circuits adjust after vestibular loss.…
This 2025 narrative review explains that cortisol normally peaks in the early morning and falls to its lowest levels in the early night. Night-shift work often shifts or flattens that pattern, causing a blunted or delayed morning peak and a less steep decline through the day. The authors link this…
