Study: Large Percentage Of Bipolar Disorder Cases "Resolve Spontaneously" By Mid-30s
A fascinating and possibly very important study came out in August in the Journal of Abnormal Psychology (one of the American Psychological Association’s journals). It concerns bipolar disorder and its course across human lifespans and the study’s conclusion that many cases of bipolar disorder “resolve spontaneously”–the authors’ term, not mine–by the latter half of the third decade of life is both startling and not surprising to me because I’ve been making a similar argument about the disorder’s natural course for a long time. It’s also not surprising to me that this study has gotten almost zero press attention–its primary finding goes so against the grain of what health reporters think they know about mental disorders and so against the grain of what psychiatry claims about bipolar disorder that it’s almost an untouchable subject.
But not for me.
1. The study was NIH-funded and its lead author is Kenneth Sher, a professor of psychology at the University of Missouri-Columbia, and two colleagues. The researchers took the data from two large and very detailed national health surveys (read the paper for more on the surveys and their diagnostic methodology) and examined it for what they call an age gradient (ie, more prevalence of bipolar disorder in one age group versus another age group). They found a significant age gradient with high prevalences of bipolar disorder among late-teens and early to mid-20somethings and much less by the time of the mid-30s–as much as 30 percent less prevalence in the 30s, about 50 percent less in the 40s and 50s and even less in 60s and older (see the graph on page 435 of the study or page 5 of the pdf). This sort of resolving as one gets older holds across both bipolar 1 and bipolar 2 diagnoses.
2. The authors use the term developmentally limited bipolar disorder to describe the phenomenon and argue that it may represent a subtype of bipolar disorder. They also note that some bipolar disorders are still present in 30 and older age groups.
3. This finding is not supposed to be happening, as the authors themselves note:
“This is contradictory to DSM–IV bipolar disorder, which is characterized as chronic, in which a history of mania is sufficient for a bipolar diagnosis. However, we remain cautious in drawing strong conclusions here, because a single follow-up after 3 years [as the underlying surveys have] does not resolve the question of reoccurrence over the life course, and the lack of noncriterial symptoms included in the interview precludes more fine-grained analysis of residual symptomatology.
4. This study is not proof that bipolar disorder fades with time. The authors call for more studies and longitudinal analyses and so on. It’s a study just begging for replication and I hope NIH and others in psychiatry get serious about its finding and undertake other research into the natural course of bipolar disorder (or disorders). Maybe Eli Lilly and AstraZeneca would like to help! Um, probably not.
5. That said, the Sher study is an important piece of evidence. Coupled with a study last year by Mark Zimmerman, a Brown University psychiatry professor, asserting that almost 50 percent of diagnoses of bipolar disorder are wrong (they are commonly cases of depression), it argues for some skepticism both within psychiatry and the media on what we think we know about bipolar disorder and what we think we know about people diagnosed with the disorder.
It also argues for doctors, mental health advocates and some in the media to stop describing bipolar disorder as chronic and lifelong.
6. The research state–and here I am paraphrasing–that one possible reason for “chronic and lifelong” tag is that much research is done in settings (commonly around public mental health systems and hospitals) where bipolar patients are more ill, for lack of a better term, than in other settings. In other words, there’s a bias built into what researchers in those setting would conclude.
7. So why would bipolar disorder be so heavily weighted towards the late-teens and 20s? Why would it then “resolve spontaneously” in the 30s?
According to emaxhealth.com:
“One possible reason for the shift, according to Kenneth J. Sher, Curators’ Professor in the Department of Psychological Sciences and a coauthor of the study, could be the stress associated with life changes and social expectations experienced by young adults ages 18 to 24. As these individuals reach their late twenties, they have begun to adjust to these changes.”
Or as researchers put it in the study:
“With respect to onset processes, late adolescence and emerging adulthood are associated with increased risk for a range of internalizing (e.g., panic disorder; Eaton, Badawi, & Melton, 1995), externalizing (e.g., alcohol use disorders; Kessler et al., 2005), and psychotic (e.g., Riecher-
Rossler & Hafner, 2000) disorders, and this increased risk can stem from a range of both developmental stressors (e.g., leaving home transition; Schulenberg, Sameroff, & Cicchetti, 2004) and neurodevelopment (Alloy, Abramson, Walshaw, Keyser, & Gerstei, 2006). Moreover, this period of life is associated with exposure to psychoactive drugs, which can presumably have relatively strong neurodevelopmental effects in vulnerable individuals during this sensitive period of brain development (e.g., Caspi et al.,
2005).”
That ought to make the blood of all genetic determinists and neuropsychopharmacologists boil over. Good.
It also ought to be a positive challenge–and perhaps ray of hope–for each and every person diagnosed with bipolar disorder.
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Posted in Furious Seasons