A comparison of characteristics of depressed patients and efficacy of sertraline and amitriptyline between Japan and the West

Background: This study was conducted to investigate the differences and similarities of the profile of depressed patients and the efficacy of the antidepressants, sertraline and amitriptyline, between Japan and the West (United States, Europe), using the Hamilton Depression Rating Scale (HAM-D) score of the individual patients. Methods: Using common selection criteria, 680 patients from three regional clinical studies were chosen for this investigation. Factor analysis of the HAM-D scores for each regional group was carried out to compare the profile of depressed patients. Analysis of covariance was used to compare the efficacy of sertraline and amitriptyline between the regions. Results: Factor analyses clearly showed three main factors (major depressive symptoms, anxiety and sleep disturbance) to be common across all three geographic regions. Higher HAM-D component scores of “Work and interests” and “Retardation” and lower ones of “Depressed mood” and “Feeling of guilt” were observed for the Japanese patients compared to the Western patients. Improvement of anxiety symptoms was marked for the Japanese amitriptyline treated patients. Limitations: Although the patient data used in these analyses were restricted by using identical selection criteria, there still remains some methodological shortcomings due to the original study design differences. Conclusions: Overall, the three main factors of depression and their magnitudes were similar between Japan and the West. The presentation of major depressive symptoms in Japanese patients differed from Western patients; this could be related to social, cultural and religious differences. Marked sedative effect for Japanese patients appeared to be due to the factor of anxiety being the strongest of the three main factors in Japanese depressed patients.