Subthreshold Bipolar: The Giant Sucking Sound

Just how many people have bipolar disorder AND what is the deal with “subthreshold” bipolar disorder? Research in the latest Archives of General Psychiatry attempts to answer just these questions. There is some strange stuff going on in this article. Suffice to say that if you hear a giant sucking sound – it is the sound of people with bipolar II and (worse) subthreshold bipolar disorder being sucked into long-term treatment with medications that lack evidence for their conditions. Warning: This is a long post. Read on…

Regarding prevalence of bipolar disorder in the US, the authors concluded that bipolar I has a one percent lifetime prevalence while bipolar II has a 1.1% lifetime prevalence. But 2.4% of people develop, at some point in their lives, “subthreshold bipolar disorder.” I don’t have major issues with how they assessed for bipolar I or bipolar II, but what, exactly, is the deal with subthreshold BP?

Well, here is their definition. To qualify for subthreshold BP, you must have had the following symptoms more than once:

A. A distinct period of persistently elevated, expansive, or irritable mood, lasting throughout at least 4 days, that is clearly different from the usual non depressed mood.

B. During the period of mood disturbance, two (or more) of the following symptoms have persisted and have been present to a significant degree:

(1) inflated self-esteem or grandiosity
(2) decreased need for sleep (e.g., feels rested after only 3 hours of sleep)
(3) more talkative than usual or pressure to keep talking
(4) flight of ideas or subjective experience that thoughts are racing
(5) distractibility (i.e., attention too easily drawn to unimportant or irrelevant
external stimuli)
(6) increase in goal-directed activity (either socially, at work or school, or
sexually) or psychomotor agitation
(7) excessive involvement in pleasurable activities that have a high potential for
painful consequences (e.g., the person engages in unrestrained buying sprees,
sexual indiscretions, or foolish business investments)

C. The episode is associated with an unequivocal change in functioning that is uncharacteristic of the person when not symptomatic.

D. The disturbance in mood and the change in functioning are observable by others.

Let’s play mix and match with these criteria.

So, if you have twice or more had a time when your mood was persistently irritable or high (A) and you didn’t need much sleep (2) and you felt pretty full of yourself (1), then you, my friend, qualify for subthreshold BPD. Or, if you, on a few occasions, were full of energy (A) and feeling much better than average (A) for, say a week, and your self-esteem was notably increased as well (1) and you got much more than usual accomplished (6) – then you also have subthreshold BPD. Let’s not forget that the second author has been saying for years that we exist on a “bipolar spectrum” with many cases of “soft bipolar” (subthreshold bipolar) being missed by unwary clinicians. Maybe he's right, but this type of definition does not give me the impression that "soft bipolar" is a big time problem.

Feel free to play more mix and match in the comment section of this post. I’m sure that most people diagnosed with subthreshold bipolar were more severely impaired than this, but these criteria are clearly too loose.

Oh, and when one goes to the comment section of the article (page 547), the authors state that their “prevalence estimate of subthreshold BPD is likely to underestimate bipolar spectrum disorder in the population”. Huh? That’s because their “definition of subthreshold BPD is still more restrictive than the definitions proposed by clinical researchers.” Oh, okay then. Because some researchers are willing to play even looser with their criteria, then we should just accept that there are a lot more people out there who have this so-called disorder.

The authors also looked at “severity of role impairment.” This analysis was based on people who had recently suffered from bipolar or subthreshold BPD. They found that among people with subthreshold BPD, 46% has “severe” role impairment, and 42% had “moderate” role impairment due to their “subthreshold mania”. Role impairment was defined as participants’ highest score of their impairment across four domains: home management, work, social life, and personal relationships. So if a participant scored no or mild impairment in three of four areas, but scored moderate on one area, then the person was counted as having moderate impairment. That’s what I call rounding up! I’d also like to see other some sort of other measure used besides this quickie disability scale. What were the real-life consequences associated with their subthreshold hypomania? That question remained unaddressed.

One other thing. On page 546, the authors state that the average number of “episodes” – either manic, depressive, hypomanic, or subthreshold hypomanic was 77.6 for those diagnosed with bipolar I, 63.6 for those diagnosed with bipolar II, and 31.8 for those diagnosed with subthreshold BPD. It strikes me that these numbers may as well have been pulled out of a hat. How the hell could somebody recall, in their life, how many “episodes” they’ve had and say, “Oh, geez, I think maybe 87.” I could be wrong, but I ain’t buying these figures.

Treatment: Warning – this is both sneaky and scary. The article goes on to essentially say that psychiatrists are much more apt to provide appropriate medical treatment for bipolar disorder than are non-psychiatrist physicians. It mentioned that those who had experienced “subthreshold” bipolar in the last year only received appropriate treatment 8.1% of the time. Earlier in the paper, appropriate treatment was defined as treatment with mood stabilizers (e.g., lithium), anticonvulsants (e.g., Depakote) and antipsychotics (e.g., Zyprexa, Seroquel, Risperdal). Rant on this to come in next paragraph -- it gets worse.

Now pay close attention. Only 3.2% of people who had a subthreshold diagnosis during their lifetime, but had not experienced an episode during the past year received “appropriate medication maintenance” treatment. WHAT?? Back up. There is scant, if any, data, saying that people with this newfangled diagnosis of “subthreshold” bipolar benefit from short-term treatment and there is not a *blanking* shred of evidence to say that people with “subthreshold” bipolar benefit from treatment with antipsychotics, mood stabilizers, or lithium in the long-term. How the hell did this section sneak through peer review? So it is now officially “appropriate” for people to receive Zyprexa or Seroquel for their “subthreshold” bipolar disorder in the long-term, even when they are experiencing no symptoms? Incredible. The paper also implies that people with bipolar II should receive constant treatment – again, where is the data to support such a recommendation. The long-term data on bipolar I treatment is also not great, but it dwarfs the data on bipolar II and “subthreshold” BP.

Funded By: The study was funded by various government agencies, the Robert Wood Johnson Foundation, and the John W Alden Trust. “Preparation of [the] article was supported by AstraZeneca.” As my astute readers know, AstraZeneca makes Seroquel, which is one of the “appropriate” treatments in this study. How does a company support the preparation of an article? Does this mean it was ghostwritten? I’m not accusing; I am just curious how a company would help to prepare an article? It would, after all, be to AZ’s benefit to suggest Seroquel was appropriate for people with “subthreshold” bipolar. Maybe I’m being too conspiratorial?

As I write this, I am thinking that I must have misinterpreted the article – there’s no way that the authors would endorse short-term and “maintenance” treatment for bipolar II and “subthreshold” bipolar given the lack of evidence. Please let me know if I misinterpreted something – I would really like to be wrong!

Hat Tip: Furious Seasons.