CBT-SAD beats light therapy over the long haul

The evidence shows CBT-SAD works just fine in late winter, and it actually outperforms light therapy over time.

There’s a solid randomized trial from Rohan and colleagues (2015, 2016) that directly compared CBT-SAD to light therapy. Both helped about equally for the current winter episode—no big surprise. But the real difference showed up the following winter. People who did CBT-SAD had roughly half the relapse rate compared to those who only used light therapy. That’s not a small gap.

Light therapy is a temporary fix. You have to keep using it every year, and it stops working the moment you turn it off. CBT-SAD teaches you skills—challenging automatic negative thoughts about winter, scheduling pleasant activities when you want to hibernate, and gradually re-engaging with the world. Those skills carry over. Starting CBT in late winter is totally fine; the protocol is typically