Being outdoors, being in the sunshine at the beach, going for a lovely hike are all crucial and important contributors to our happiness. So when we don't have these because of the weather and because of the dark this can also just contribute to a natural behavioral and environmental decline in our well-being. One of the methods they'd probably suggest first to survive seasonal depression is called bright light therapy. It rests on the assumption that the presence and absence of light, mainly sunlight, is the primary contributing factor to seasonal depression.