In order to study depression in Japan and in the West, the differences in presentation were compared from various dimensions. Based on these study results, the treatment effects of the antidepressants and their side effects were also compared.

"Depression" between Japan and the West was compared from the following perspectives: 1) clinical presentation, epidemiology and course of illness; 2) psycho-pathological aspects; 3) patho-pysiological and neurobiological aspects; 4) treatment algorithms. Although characteristics of the patients prior the disorder differed to some extent, it was concluded that no great differences existed. Subsequently, comparisons were made between the study designs employed for verifying efficacy of the drugs. These included patient selection, experimental methods and efficacy variables. The following were noted as points of difference: placebo controlled studies are not conducted in Japan due to the circumstances that make the acceptance of a placebo arm difficult; and individual items of the Hamilton Rating Scale for Depression are not identical.

In addition, results will be presented comparing clinical studies of Selective Serotonin Reuptake Inhibitors (SSRIs) that have been developed in both Japan and overseas.