Community study clarifies rapid-cycling bipolar disorder characteristics
MedWire News: A community epidemiological profile based on surveys in 10 diverse countries confirms most but not all current clinically based knowledge on rapid-cycling bipolar disorder (BPD-RC).
Clinical studies suggest that BPD-RC is present in 12-24% of people with BPD, and is more common in women and associated with earlier age at onset, greater illness burden, and relatively higher treatment resistance than non-rapid-cycling bipolar disorder (BPD-nonRC).
However, there have been no community-based epidemiological studies to clarify unresolved issues relating to the disorder, such as whether it is an iatrogenic condition, an arbitrary entity in a dimensional framework of conceptualizing episode frequency in bipolar disorder and, more generally, whether current knowledge about this disorder is biased by a higher probability of help-seeking.
Sing Lee, from the Chinese University of Hong Kong, and colleagues used the Composite International Diagnostic Interview to examine the prevalence, severity, comorbidity, impairment, suicidality, childhood adversity, and treatment of BPD-RC and BPD-nonRC in 54,257 participants in 10 countries (Brazil, Colombia, Mexico, USA, Bulgaria, Romania, India, Japan, Lebanon, and New Zealand).
The 12-month prevalence of BPD-RC was 0.3%. Roughly a third and two-fifths of participants with lifetime and 12-month BPD, respectively, met the criteria for rapid cycling.
Confirming clinical findings, BPD-RC was associated with younger age at onset, higher persistence, more severe depressive symptoms, greater impairment from depressive symptoms, more out-of-role days from mania/hypomania, more anxiety disorders, and an increased likelihood of using health services, compared with BPD-nonRC.
The researchers note that the frequency of BPD-RC was higher in their community study than in some previous clinical studies, which could reflect greater help-seeking in these patients.
But they point out that 83.4% of patients with BPD-RC had received lifetime treatment, suggesting that the condition was indeed very impairing. Also, psychiatrists were not commonly involved in the treatment of BPD-RC patients, refuting the suggestion in some clinical studies that BPD-RC is a primarily drug-induced condition.
In contrast with previous clinical studies of BPD-RC, the present study found that participants with 12-month BPD-RC did not have a significantly elevated risk for suicidality, compared with their peers with BPD-nonRC and there was no association between BPD-RC and gender.
Although both BPD-RC and BPD-nonRC were associated with childhood neglect and abuse, BPD-RC was more strongly associated with childhood neglect than BPD-nonRC, whereas there was no significant difference for abuse.
Writing in the British Journal of Psychiatry, the researchers conclude that the DSM-IV does not fully capture the spectrum of rapid cycling and mixed episodes, and that a refined fully-structured instrument that can validly assess the core characteristics of BPD-RC needs to be developed.
“Dimensional measures of these characteristics are desirable for resolving uncertainty about the optimal boundary distinctions for BPD-RC as rapid cycling may be a dimensional course specifier,” they say.
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By Joel Levy