Actually, it's kind of ironic (at least for us in the Northern Hemisphere) to say Happy Solstice, since general depression can be linked to the lack of sunlight in the winter months.
Get's worse after the holidays.
Oh but we are happy that the sunlight is now returning. When I lived in Sweden, it was always the loss of daylight that depressed me. Once you get to the solstice, you know it's getting better!