Our bodies know this, even if our monkey minds often get too distracted by the bright shininess of modern technological existence to pay attention. Of course the seasons affect us.
So what can you do? Your therapist friend may be right, maybe you don't have the sort of seriously sad SAD that requires serious intervention, but maybe you have subsyndromal seasonal affective disorder, the milder kind (I'm willing to bet that I do, and we have plenty of company). Maybe you have low kisspeptin. Maybe you just don't like the dark. You could do the light-box therapy anyway, no matter what your friend says, and just see if it works. You could take a lovely "get your groove back" beach vacation. You could make sure you get out of the office every day at lunch. Or you could just figure that having a low libido for three months a year is not the most horrible thing that could possibly happen, and hibernate until it's over. You wouldn't be the first mammal to just pull the covers over her head and wait for the solstice. Your next mate can wait.
See Andrea's other column at carnalnation.com.