 Sample Size Calculation A total of 232 patients equally divided into two groups will achieve 90 percent power, 5 percent level of significance using one sided hypothesis and an anticipated difference in the response rate of 20 percent in the two groups with 30 percent response rate among SSRI group and atleast 50 in the combination treatment group. Considering 15 percent drop out in each group an additional sample of 36 patients equally divided into two groups will be recruited to make a total required sample of 268 patients. 