Bipolar Spectrum Diagnostic Scale (BSDS) is a diagnostic tool used to determine if someone with mood disorder symptoms has bipolar disorder. The Bipolar Spectrum Diagnostic Scale contains nineteen sentences.

S. Nassir Ghaemi, M.D., M.P.H. refined the Bipolar Spectrum Diagnostic Scale originally developed by Ronald Pies, M.D. This diagnostic tool is considered sensitive and can detect all variations and levels of severity of bipolar disorder.

Pies was motivated to design the Bipolar Spectrum Diagnostic Scale after he had experience with many people who have treatment-resistant depression that was later determined to be undiagnosed bipolar spectrum disorder. Bipolar spectrum disorder is not in the Diagnostic and Statistical Manual (DSM) which is used to diagnose mental illnesses.

Some mental health professionals use the unofficial diagnosis of bipolar spectrum disorder to refer to people who have bipolar symptoms, but their symptoms are not severe enough for an official bipolar disorder diagnosis. Mild bipolar disorder is sometimes called soft bipolar disorder or soft bipolar spectrum disorder.

The Bipolar Spectrum Diagnostic Scale has two sections. The first section has nineteen sentences that describe the main symptoms of bipolar disorder. The patient is to check the sentences that describe their feelings or behaviors.

The second section contains a rating scale. The patients must rate how well the nineteen sentence narrative of section one as a whole fits their personal experiences. The number of the sentences checked in first section is the score for that section.

The second section is scored according to how the narrative is rated by the patient. If the patient indicates that the story fits them very well or almost perfectly, six points are added to the person’s score. Four points are added if the patient says the narrative fits fairly well.

Two points are added if the patient’s rating is that the story fits to some degree but not in most respects. No points are added to the patient’s score if the person says the story does not describe them at all.

Bipolar disorder is considered highly likely if the patient’s score is nineteen or higher. If the score is eleven to eighteen, there is a moderate probability of bipolar disorder. There is a low probability if the score is six to ten. Bipolar disorder is considered very unlikely if the score is under five or less.