A group of researchers is now advocating the expansion of diagnostic criteria for bipolar disorder to include subthreshold mania in the fifth edition of the Diagnostic and Statistical Manual of Mental Diseases. Kathleen R. Merikangas, PhD, of the National Institute of Mental Health in Bethesda, Md., and colleagues, found that of the study’s sample of more than 9,000 people almost 40% had a history of major depressive disorder accompanied by periods of hypomania that were just outside of the parameters for bipolar disorder. The researchers felt that these individuals would benefit from a mood stabilizer in addition to antidepressants and as such are in support of the proposal of a broadening of DSM criteria for bipolar disorder. “Such an expansion of the bipolar concept would likely lead to important changes in the treatment of patients who are undiagnosed or misdiagnosed despite elevated morbidity and mortality rates,” the group wrote. Click here to read an article from Psych Centeral that discusses this study more.