Major depressive disorder (MDD) is one of the most common medical conditions worldwide (World Health Organization (WHO), 2001), and directly affects 10–15% of the world’s population annually. MDD is associated with reduced quality of life, increased personal burden, and substantial direct and indirect costs to individuals, families and society as a whole (WHO, 2001; Philip et al., 2010). In the US, in any given year, between 13.1 million and 14.2 million individuals will experience an episode of MDD (Kessler et al., 2003) and recent epidemiological studies published by WHO predict that MDD will become the leading cause worldwide of overall disease burden by 2030 (WHO, 2004). The impact of an episode of MDD on an individual is often further complicated as it is accompanied by substantial medical and psychiatric morbidities, psychological setbacks and impairments, regressive behaviors, feelings of social incompetence and apprehension about the future.