Anyone would be happy to concede defeat in a competition between who has the greatest number of major depressive episodes (MDEs), and how severe they are.
The loser won’t even ask for a booby prize.
But it turns out we do have a winner, folks, as a publication just this month determines for good.
As summarized in the research of Carmen Moreno, a psychiatrist from Hospital General Universitario Gregorio Marañón in Madrid, Spain, and colleagues, people with bipolar disorder (BD), both Bipolar I (BD-I: defined by the presence of a manic episode) and Bipolar II (BD-II: defined by the presence of a hypomanic episode–a more ‘mild mania’ or a ‘mania light’) experience more–and more severe–MDEs than those diagnosed with Major Depressive Disorder (MDD) [are you still with me, with all this alphabet soup? It can get quite complex.]. And Bipolar I places first in a head-to-head contest with Bipolar II, as well.
Seems like it’s a sort of a sliding scale of quantity and severity, with BD-I the top scorer, BD-II in a solid second, and MDD taking the bronze.
Not that those with MDD should feel bad–someone has to come in last, and this seems a good enough competition to lose.
Moreno’s study, just published in the May 2012 issue of Bipolar Disorders, utilized information from the National Epidemiologic Survey on Alcohol and Related Conditions (2001–2002). Their findings were based on face-to-face surveys of over 433,000 American adults–nationally representative–including 5695 subjects with lifetime MDD, 935 with BD-I, and 494 with BD-II.
The analysis quickly emphasized the statistically significant difference in severity level for each diagnosis.
BD-I patients had the greatest number of symptoms of depression during MDE’s, averaging 8.1, while BD-II experienced 7.6, with MDD rounding out the symptomatology chart with an average of 7.4 symptoms of depression.
They researchers conclude that, during major depressive episodes,
all symptoms of depression, except depressed mood and low energy, were more common in BD-I than MDD individuals. [See table at the end for specific symptomatology experienced by each subgroup.]
But depressive episodes are not just more severe for bipolar patients–they are more frequent, as well.
Moreno’s group found that the lifetime number of depressive episodes was highest for BD-I patients, who had the greatest mean number of lifetime MDEs with 8.9. That was followed by BDII patients, experiencing an average of 5.9 MDEs, with those with MDD experiencing only 4.7.
These results indicating more frequent MDEs for the course of BD as opposed to MDD replicate a finding published numerous times before.
For example, in a 2010 study entitled, “A population-based analysis of distinguishers of bipolar disorder from major depressive disorder,” the researchers conclude that
Clinical variables significantly associated with BD included greater number of lifetime depressive episodes. . . [emphasis mine]
And in an earlier study, Franco Benazzi, with the Department of Psychiatry for the Italian National Health Service, studied BD-II as compared with MDD and found those with BD-II had “more recurrences” than those suffering from MDD.
In summation of their own, most up-to-date findings, Morena et al conclude that:
(i) most depressive symptoms. . .were more common in BD-I, followed by BD-II, and least common in MDD subjects; (ii) subjects. . . with BD-I had a higher number of depressive episodes than those with BD-II and MDD; . . .and (iv) analyses . . .identified a severity trend across diagnoses (higher for BD-I, followed by BD-II, and last, MDD). [emphasis mine]
Their findings of the clear distinction between the three diagnoses replicate those from a 2002 article, “Clinical and demographic features of mood disorder subtypes,” which utilized them in a different way–to separate out Bipolar I from the other two illnesses.
The researchers clearly state the distinctions between the three disorders, noting that BD-I [referred to as BP-I, just for more fun and confusion] stands out on its own in terms of symptomatology. Their data, they assert
support the view that BP-I disorder is quite different from the remaining mood disorders from a . . . .clinical perspective with BP-II disorder having an intermediate position to [MDD], that is, as a less severe disorder.
They conclude on the optimistic note that this finding
may help in the search for the biological basis of mood disorders.
Perhaps. Anything could help, I suppose.
But Moreno’s study offers a more nuanced view. Rather than declaring the disorders ‘different’ or ‘similar,’ the researchers view BD-I, BD-II, and MDD as existing on a ‘spectrum of severity of MDE.’
It’s a fascinating article–and discovery–but how should this concept of a spectrum of severity be incorporated into psychiatric diagnosis, in a way that will actually help the diagnostician and patient alike?
Enter the DSM-5. . . and, for once, it seems, it has posed an idea people haven’t criticized. It almost didn’t seem possible anymore.
In all the Diagnostic and Statistical Manuals of Mental Disorders so far, disorders are arranged by category, with a specific list of symptoms for each illness. In this ‘categorical system,’ a patient either has the symptom–or doesn’t. The said patient must have a certain number of symptoms to receive a diagnosis.
Because the criteria for diagnosis are simply ‘yes/no,’ there is no way in the previous DSMs to account for the severity of the disorder.
But Morena et al assert that the ‘spectrum of severity’ they discovered would suggest utility of what’s called ‘dimensional assessments’ in classification, which is right where DSM-5 is at.
The DSM-5 Committee is indeed prepared to insert dimensional assessments into classification, which would enable a clinician to rate not just the presence of a symptom, but also the severity, opening up more diagnostic insight into the types of distinctions Morena found between what seem, at first, to be similar episodes. [See "Frequently Asked Questions" on the APA's DSM-5 page for further explanation of dimensional assessments.]
And no one need feel bad–or, in fact, superior–about losing or winning the depression contest. Each person gets their own spot on the ‘spectrum of severity’–and from there they can worry about appropriate treatment response (and, if they’re truly competitive, they can think long and hard about whether this is a competition really worth winning).
In the meantime, winners and losers and tie-breakers alike can take comfort in knowing that their experiences will be better reflected and diagnosed when the DSM-5 makes its dilatory appearance. Until then, remember the pearls of wisdom we’ve garnered from the ever-so-psychologically-aware world of sports:
It’s not whether you win or lose, it’s how you play the game.
The suffering of depressive episodes is great, the road is long–but keep playing, just keep playing.
TABLE: PREVALENCE OF DEPRESSIVE SYMPTOMS PER DISORDER*
Most symptoms of depression were more common among BD-I subjects than MDD:
increased appetite/weight gain*
thoughts about death
difficulty making decisions*
*All the asterisked symptoms were more frequent among BD-I than among BD-II patients, as well.
But, showing that symptoms have somewhat of a sliding scale, BD-II subjects showed more:
difficulty making decisions
than those with MDD.
*[Moreno et al]
Benazzi F. Clinical differences between bipolar II depression and unipolar major depressive disorder: lack of an effect of age. Journal of Affective Disorders 2003; 75:191–195.
Moreno C, Hasin DS, Arango C, et al. Depression in bipolar disorder versus major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Bipolar Disorders 2012; 14:271–282.
Schaffer A, Cairney J, Veldhuizen S, et al. A population-based analysis of distinguishers of bipolar disorder from major depressive disorder. Journal of Affective Disorders 2010; 125(1-3):103-110.
Serretti A, et al. Clinical and demographic features of mood disorder subtypes. Psychiatry Research 2002; 112(3):195-210.