This study aims at examining the interrelationships between suicide rates and prescription of antidepressant agents based on the health insurance data from persons who had diagnoses of ICD: 290-319 or were prescribed with antidepressant agents during the period from 1998 to 2006. The investigators plan to first perform correlation analyses between the trends of suicide rates and prescription of antidepressants during the study period after taking into accounts potential confounding factors; analyses by age, gender groups and by administrative regions will also be performed. Besides, the investigators plan to analyze the change in the prescription pattern of psychotropic agents in Taiwan during the study period, with the particular focus on that of newer antidepressant drugs. The prescription of psychotropic agents in both psychiatric and non-psychiatric diagnoses will be explored.