Shorter days and dark afternoons can trigger depression. Here’s how to fight back

Shortening daylight and the shift to darker afternoons can bring on seasonal affective disorder (SAD), a form of depression that usually starts in autumn and eases in spring or summer. The article explains that researchers are investigating how the eyes’ response to blue light may affect mood and alertness, while noting that no single cause of SAD has been established.

Treatments include antidepressants, light therapy, cognitive behavioural therapy (CBT), regular sleep and outdoor walks, even on cloudy days. Research-backed light therapy uses a device emitting about 10,000 lux for 30 minutes each morning; prices range from around $50 to more than $400, and its benefits may fade when use stops. CBT may have more lasting effects, and planning manageable enjoyable activities can help people re-engage socially.