(AP) – As winter approaches and daylight hours grow shorter, people prone to seasonal depression can feel it in their bodies and brains.

The millions of people estimated to have seasonal affective disorder, or SAD, typically have episodes of depression that begin in the fall and ease in the spring or summer. One trigger for SAD is when clocks revert to standard time, which happened Sunday across much of the U.S., bringing darker afternoons. A milder form, subsyndromal SAD, is recognized by medical experts, and there’s also a summer variety of seasonal depression, though less is known about it. (Read More)