Overview
- UK Biobank sleep data across four years show longer sleep with more sleeplessness in winter, with findings due at the British Sleep Society conference in Brighton.
- Researchers report seasonal shifts in expression of more than 4,000 protein-coding genes, strengthening evidence for a physiological basis to SAD.
- Clinicians advise morning bright light therapy at 10,000 lux for 30–60 minutes, with CBT tailored for SAD shown to be similarly effective and medication used when appropriate.
- Early steps are recommended as daylight wanes, including outdoor light exposure, regular exercise, consistent sleep routines, vitamin D intake, and maintaining social contact.
- SAD affects millions—about 10 million in the US—while UK estimates suggest one in five experience milder winter blues and roughly 2% meet criteria for SAD, with women reported as diagnosed about four times more often.