Young women in northern latitudes get hit hardest by late-winter SAD

Young women living far from the equator face the highest risk for severe late-winter seasonal affective disorder.

The numbers are pretty consistent across studies. Women are diagnosed with SAD about 2-4 times more often than men. Age peaks in your 20s and 30s. And the farther you live from the equator, the bigger the light gap in winter — places like Scandinavia, Canada, and the northern US see the worst rates.

Late-winter is especially brutal because by February or March your body has been starved of bright light for months. The cumulative effect makes the dip deeper. Combine that with being a younger woman who’s already more prone to seasonal mood shifts, and you’re in the highest-risk bucket.

I’m not saying men or older people don’t get it — they do. But if you’re a woman under 40 living above 40° latitude, you’re the prime candidate for a rough late-winter.

If that’s you, start light therapy in early January, not March. Future You will notice the difference.