Please elaborate. I'll get the popcorn. For those interested, bipolar disorder is defined and classified by the Diagnostic and Statistical Manual of Mental Disorders, which through its inclusion says that the APA defines it as a mental disorder. (illness is commonly substituted for disorder around the world). While it is true that bipolar is currently classified under mood(not emotional) disorders, all fall under the hierarchy of mental disorder(or illness). Also notable is the fact that in the new DSM-V being released this year, bipolar will get its own chapter and the hierarchy of it being classified under the subheading "mood disorder" is going away. "Additionally, criteria for bipolar disorder will now include an emphasis on changes in activity and energy—not just mood—to reflect findings from recent research.(APA news update on DSM-V, Feb 2013)"