Double depression refers to the co-existence of major depressive disorder (MDD) and persistent depressive disorder (PDD), (the latter was previously referred to as dysthymia). Research has shown that double depression tends to be more severe than either MDD or PDD alone and that individuals with double depression experience relapse more often than those with either MDD or PDD alone. However, there is some research that indicates few differences exist between double depression, MDD, and PDD; as a result, those researchers conclude that double depression is not a distinct disorder. The literature that details the pharmaceutical treatment of double depression is sparse. Although there are studies that demonstrate that certain medications, such as selective serotonin reuptake inhibitors (SSRIs), are effective methods of treatment, those studies lack placebo controls; therefore, the studies' conclusions are questionable. Research has found that, as is the case with other depressive disorders, pharmaceutical and therapeutic treatments combined are more effective than the use of either form of treatment alone. Individuals with double depression tend to experience more functional impairment than those with either MDD or PDD alone. As a result, researchers emphasize the need for unique treatments for double depression to be developed and implemented. Presentation Individuals with double depression meet the DSM-5 classification criteria for both MDD and PDD. Goldney and Fisher (2004) determined that, in a sample of 3,010 individuals from southern portions of Australia calculated a prevalence rate of double depression of 2.2%. Jonas et al. (2003) reported a prevalence rate of double depression in the United States of 3.4%—based upon an assessment of 7,667 Americans. The prevalence rate of double depression can be compared to rates of PDD at 6.2%, major depressive episode (MDE) at 8.6%, and major depressive episode with severity (MDE-s) at 7.7%. Keller and Shapiro (1982) found that 26% of patients within a sample of 101 met the criteria for both MDD and PDD; however, the aforementioned sample is much smaller—and much more inclined to inaccuracies—than the samples (3,010 and 7,667) described above. Thus, double depression is less common than other forms of depression, but it is still a form of depression that warrants medical attention in the form of behavioral therapies; pharmaceutical treatments; or, both (Miller, Norman, and Keitner, 1999). The characteristics of those with double depression tend to be more severe in nature than those associated with those who have either MDD or PDD. Levitt, Joffe, and MacDonald