zlacker

>>ivank+(OP)
A recent Cochrane review found very little high quality evidence in either direction:

http://www.cochrane.org/CD011269/DEPRESSN_light-therapy-prev...

It's not clear to me why light therapy is considered as a well-researched treatment.

>>sambe+Ad1
I'd put a black crow's feather behind my ear if I thought it would help me get through winter.

In other words, placebo effect is still an effect. The treatment being chemically vs. psychologicaly responsible for that isn't a concern for the subject, only the researcher.

>>moron4+ih1
The problem is that placebo effect is usually close to nil, when it even exists. Most of the time what is actually happening is regression to the mean, not placebo efficacy.