Dr. Jim Phelps is the author of a textbook on bipolar spectrum disorders, A Spectrum Approach to Mood Disorders: Not Fully Bipolar But Not Unipolar—Practical Management (W. W. Norton & Company) as well as two self-help books on bipolar disorder. He conducted some of the early studies on dark therapy out of his private practice in Oregon, and we caught up with him to learn about this novel treatment for bipolar disorder.

Borderline personality disorder (BPD) and bipolar disorder frequently co-occur (numbers range from 8% to 18%), although they are distinct clinical entities (Paris J et al, Compr Psychiatry 2007;48(2):145–154). A proper diagnosis guides the most effective treatment, but you’ve probably faced the difficult challenge of diagnosing these conditions, which share several clinical features.