INTRODUCTION AND REVIEW Depression refers to a wide range of mental health problems characterised by the absence of a positive affect (a loss of interest and enjoyment in ordinary things and experiences) and a range of associated emotional, cognitive, physical and behavioural symptoms. Depression is different from typical mood fluctuations and transitory emotional reactions to day-to-day challenges (WHO, 2018). However, distinguishing the mood changes between depression and those occurring 'normally' remains problematic: persistence, severity, the presence of other symptoms and the degree of functional and social impairments form the basis of that distinction. Depression affects people from all age groups, starting from childhood to elderly, across gender and economic, social and cultural backgrounds resulting in a poor quality of life, impaired functioning and huge socio-economic burden (WHO, 2015). Today, depression is one of the major health concerns across the globe. This is not only because of its high prevalence rate but also because of its high reoccurrence rate and the lifelong disability that it causes. Globally, it is estimated that 322 million people are affected with depression (WHO, 2017). In 2002, depression accounted for 4.5% of the worldwide total burden of disease and it is estimated that by 2020, the burden of depression will increase to 5.7% of the total burden of diseases (WHO, 2002). This means that by 2020, depression will be the second leading cause of world disability (WHO, 2001) and by 2030 it is expected to be the largest contributor to disease burden (Bromet el al, 2011; Thirunavukarasu and Thirunavukarasu,2010; ?st?n, Ayuso,