Risk factors of cycle acceleration in acutely admitted patients with bipolar disorder
Abstract
Obje ctive: To identify risk factors associated with cycle acceleration
(CA), that is, progressive decrease in duration of syndrome-free
intervals between affective episodes, in acutely admitted patients with
bipolar disorder (BD).
Method : All patients ( n = 210) with BD I (67%) and BD II (33%)
(DSM-IV) acutely admitted to a hospital serving a catchment area were
compared in retrospect with regard to a positive or negative history of
CA. Putative risk factors of CA with a P-value <0.05 in uni-variate tests
were secondly entered into a logistic regression model.
Res ults: The logistic regression model was statistically significant
(P < 0.0001) and explained between 45.3% and 60.5% of the variance
of CA status. 83.7% of the cases were correctly classified with a
sensitivity of 87.2% and a specificity of 80.4%. Unique significant risk
factors of CA were increasing severity of affective episodes (odds ratio
(OR) = 28.8), BD II (OR = 3.3), hypomanic/manic episode induced by
an antidepressant and/or alcohol (OR = 3.3), and female gender
(OR = 3.1).
Conc lusion: The clinical factors associated with CA may help targeting
patients with BD with a course aggravation, and are in line with
previously reported neuropathological processes of illness progression.
Key words: bipolar disorder; in-patient; cycle
acceleration; risk factors