In the two articles below, we learn of the evidence that debunks this myth, although one study warns of a possible "rebound effect" following Christmas holidays when certain individuals, especially the bereaved elderly, return back to their daily routines where they are more likely reminded of previous losses and loneliness.
"According to the most recent statistics from the Centers for Disease Control and Prevention, the suicide rate is at its lowest in December. And studies dating back to the 1980s and conducted across the globe have investigated the link between the holiday season and suicide, finding again and again that Christmas is associated with a decrease in suicide, both attempts and completion (the latter being the official term for people who both try and succeed in killing themselves). "
For the full articles, click the links below:
http://www.theatlantic.com/health/archive/2015/12/no-suicides-dont-rise-during-the-holidays/419436/
http://nymag.com/scienceofus/2015/12/suicides-dont-really-spike-around-the-holidays.html?mid=twitter_nymag