George McCann has been diagnosed with a subtype of bipolar disorder called the "fear of harm" profile, and finds that a prescribed dose of ketamine every few days alleviates his symptoms. Michael Rubenstein for NPR hide caption

itoggle caption Michael Rubenstein for NPR

Linea Johnson, left, and her mother, Cinda, in May 2012 at the launch of their book on the family's struggle with Linea's bipolar disorder. Tommy Voeten hide caption

itoggle caption Tommy Voeten