According to one equation devised by Dr. Cliff Arnall, a British
researcher from Cardiff University, Jan. 24 is 2011's most depressing
day, termed "Blue Monday." While some debate the exact date, his
formula for this bleak prediction takes into account factors like
post-holiday blahs and debt, failed New Year's resolutions and, this
year, the nasty chill that has reached much further south than usual.
This particular peak in seasonal affective disorder (SAD) isn't the
only time that we're prone to feeling low.