Yes, it’s very necessary. Bipolar Disorder is deadly and there is still stigma that needs to be eradicated.
From Huffington Post:
But a bipolar day? Are there that many people with it to support having its own day?
There are 450 million people worldwide with mental illness. Of those it is estimated that the global prevalence of bipolar disorder is between 1 and 2 percent and has been said to be as high as 5 percent, which is three times all the diabetes and 10 times all the cancers combined.
See article:
http://www.huffingtonpost.com/muffy-walker/why-a-world-bipolar-day_b_6878976.html?