This system was described in an article by Harvard’s Director of the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD), Dr. Gary Sachs. It’s since been validated thrice. Aiken, Ma, Mosolov The Index represents a “clinical” diagnostic approach — what matters to doctors and patients when they are trying to understand a particular patient’s mood problems. Unlike a DSM-based diagnostic system which emphasizes separate diagnostic categories, the Bipolarity Index places patients on a spectrum. As you’ll see, it also emphasizes diagnostic features other than hypomania.
Five dimensions (including the DSM as one)
Dr. Sachs’ system was developed with several colleagues at Harvard, including Dr. Nassir Ghaemi, whose name you will find mentioned frequently on this website, as he is a well-known researcher of this “spectrum” way of looking at bipolar diagnosis. The system considers 5 “dimensions” of bipolarity. Note that the presence of hypomania or mania is only one of the five dimensions. All the others receive equal weight, for now (the system has not been subjected to the usual tests a “diagnostic instrument” would receive; thus we do not yet know how much weight each of these 5 dimensions should carry):
- Hypomania or mania
- Age of onset of first mood symptoms
- Illness course and other features generally only visible over time
- Response to medications (antidepressants and mood stabilizers)
- Family history of mood and substance use problems
Update 2016: the Index now has three validation studies showing that it can accurately detect patients with bipolar disorder.Aiken, Ma, Mosolov These studies validate the weighting of the five dimensions: 80% to the non-manic markers, only 20% of the weight to the DSM criteria.
But I think the value of the Bipolarity Index goes beyond this validation of the non-manic markers. It allows us to change the diagnostic question from “Do you have it or do you not?” to “How bipolar are you?” — just as originally described by one of its chief architects.
Link to Key Table
LINK TO FULL TABLE (which doesn’t fit here…)
Interpreting a Bipolarity Index score
Dr. Sachs’ article indicates that in their experience so far, most Bipolar I patients score above 60. Note that’s Bipolar I, not Bipolar II or other more subtle variations, which would presumably have lower scores. Notice that a patient can “get points” for many different features of bipolarity, not just hypomania or mania. In fact, she could get 60 points even without any history of hypomania or mania at all, you see? For example, she might have had: her first depression at age 18 (20 points); post-partum depression (5 points); more than 3 episodes of depression (5 points); agitation while taking an antidepressant (10 points); and have a sister with clear bipolar disorder (20 points). But beyond this — Bipolar I patients score above 60 — we do not yet know what a particular “score” might mean. Therefore this table is not offered to help you score patients (or yourself). It is presented to demonstrate that some of the most respected mood experts in the world are now using a system which approaches bipolar disorders as existing on a “spectrum”, rather than a yes/no, you-have-it-or-you-don’t matter. Dr. Sachs himself explains this in an interview conducted shortly after this article, excerpted here. If after all this you still want a “fine-tooth comb” to look for hypomanic/manic symptoms — only 1/5th of the points here, but still the major diagnostic feature in the official DSM system — here is a list of such symptoms.