Late winter blues are normal. Seasonal depression is not.

The key difference is severity and impairment. Subsyndromal SAD is what most people call the winter blues — mild fatigue, lower mood, craving carbs, but you still function. Full SAD hits harder: you can’t get out of bed, your work suffers, relationships strain, and you might have thoughts of worthlessness or even suicide.

In late winter, both can look similar because everyone is sick of the dark. The real test is whether you’re still showing up. Subsyndromal SAD means you drag yourself through the day, but you make it. Full SAD means you stop trying. You cancel plans, miss deadlines, or sleep 12 hours and still feel exhausted.

Clinical