Depression is one of the most common psychological problems, affecting nearly everyone through either personal experience or through depression in a family member. It has been estimated that one in five Canadians will suffer with depression or low mood over their lifetime. Symptoms can persist for days, months, and/or years, disrupting personal lives and careers and causing great unhappiness. It causes pain and suffering not only to those who have a disorder, but also to those who care about them. In the past decade, great strides have been made in understanding these disorders and how to treat them.