Overview
- Four years of UK Biobank data covering roughly 500,000 people show that sleep runs longer but is more disturbed in winter, with the findings set to be presented at the British Sleep Society conference.
- Researchers highlight light as the primary regulator of the body clock, with reduced daylight in darker months linked to mood changes through circadian disruption.
- Clinicians describe bright light therapy as first-line care, typically using a 10,000-lux light box for 30 to 60 minutes in the morning, with timing and dose emphasized as crucial for benefit.
- Cognitive behavioral therapy tailored for seasonal patterns can match light therapy in effectiveness, while routine exercise, morning outdoor light, vitamin D intake, and social connection are advised as supportive measures.
- Prevalence estimates include about 2% experiencing full SAD in the UK with around one in five reporting milder winter dips, and roughly 10 million affected in the US, with women diagnosed at far higher rates than men.