Development of a DSM test battery to determine depression-like marmoset

Depression is a serious and high-incidence mental disorder that can lead to suicide. Despite much depression research using humans and rodents to date, it has been difficult to completely overcome depression and elucidate its etiology. Marmoset monkeys have been utilized to study neuropsychiatric disorders in recent years. Since the clinical diagnostic criteria for psychiatric disorders are mainly based on multiple behavioral changes, test battery systems, a multifaceted and comprehensive strategy, are applied to depression research. Here, we devised a test battery with six tests to investigate depression-like symptoms corresponding to clinical criteria and set criteria for a test indicator-based judgment. We did a usability confirmation experiment using a drug and judged three of nine marmosets as depression-like. This rate is comparable with the incidence rate of human patients; i.e., 10-30% of patients who received reserpine treatment suffer from depression. Thus, we propose the test battery we constructed in this study will contribute to the study of depression.