1.1 Introduction: Depression is commonly understood as a feeling of sadness of an individual or a general impairment of the normal functioning of the individual which has a direct effect on the individual himself as well as his family and friends. A man named Hippocrates, described as the father of Western medicine, first described an individual's low mood as "melancholy." Hippocrates described melancholy as having specific mental and physical symptoms. Over its 2,400-year history, the term melancholy has changed its meaning numerous times. The term melancholy was often used very broadly in Greco-Roman Antiquity to describe states of the individual which can today be described as "schizophrenic". The term melancholy is taken from the Latin transliteration of the Greek term melancholy. In Greece, the term described a mental disorder that involved a continuous low mood as well as feelings of fear that sometimes meant "biliousness" and in medical parlance, this term described "nervous" or "crazy" behavior. The term is taken from the words melaina chole, translated into Latin as astra bilis and into English as black bile (Medicalnewstoday.com, 2009). The affect, mood or emotions caused by depression or melancholy have been well known to humans for thousands of years. It was once believed that clinical depression did not have as wide a range of symptoms as melancholy. Symptoms of melancholy include discouragement, despondency, general sadness, fear, anger, obsessions and also delusions. Abraham Lincoln is believed to have suffered from melancholy, known today more commonly as clinical depression (Medicalnewstoday, 2009). The number of individuals suffering from depression is not exa...... middle of paper ...... anxiety (Fava et al., 1997; Flint and Rifat, 1997; Davidson et al., 2002) . A recent large-scale multicenter study of potential ATR-related predictors took place in Europe and found 5 main clinical predictors in order of strength (1) current suicide risk (2) comorbid anxiety disorder (3) sex (4) seasonal profile (5) non-response to the first antidepressant during life (Oswald et al., 2005). Non-psychiatric comorbidities have been found to be predictors of TRD (Iosifescu et al., 2004). It has been found that patients with high serum cholesterol levels do not respond as well to Fluoxetine treatment as patients with normal cholesterol levels (Sonawalla et al., 2002). Late-life depression has been associated with comorbid somatic disorders such as circulatory problems, arthritis, or skin problems (Oslin et al.., 2002).