The obseration of increasing symptom seerity from one category to the next reinforces "the alidity of the spectrum concept of bipolarity," the researchers note. 研究者把一個(gè)分類(lèi)到另一分類(lèi)的嚴重癥狀進(jìn)行了補充,從而形成一個(gè)有效的雙重精神障礙的疾病譜系,研究者并對此進(jìn)行了特別說(shuō)明。