This paper is a general review of persistent depressive disorder. By reviewing pertinent literature, this paper focuses on etiology, impacts, treatments, and recommendations for future improvement. Persistent depressive disorder affects all ages people. Young people with persistent depressive disorder need special attention because if not receiving treatment early, it will deteriorate into major depressive disorder, especially in early-onset patients. Although the persistent depressive disorder has been shown to have strong associations with other depressive disorders and even affect cognition, such as spatial working memory, relationships are still not clear and not empirically tested. Several factors will increase the likelihood of persistent depressive disorder, including family and heredity factors. In addition to the worsening of the disease due to untimely treatment, there is a high chance of recurrence in the future. This is not a disorder that can be easily cured and can take years to fight it. In all, this study provides new thinking for the understanding of persistent depressive d in both theory and practice.