Differences in course of illness between patients with bipolar II disorder with and without epileptiform discharges or other sharp activity on electroencephalograms: a cross-sectional study.

BACKGROUND: A diagnosis of bipolar II disorder requires that the symptoms cannot be better explained by a medical condition. Epilepsy is in some cases associated with an affective syndrome mimicking an unstable bipolar II disorder. Epileptiform discharges on electroencephalograms (EEGs) are typical, but not pathognomonic, for epilepsy. A previous study has found a high frequency of epileptiform discharges and other sharp activity among patients with bipolar disorder. The aim of the study was to identify if epileptic discharges or other sharp activity per se are associated with an altered course of illness among patients with bipolar II disorder. METHODS: Eighty six patients diagnosed with bipolar II disorder at two psychiatric departments were interviewed about prior course of illness and assessed with EEGs. The patients were split into two groups based on the presence (n = 12) or absence (n = 74) of epileptiform discharges or other sharp activity. Wilcoxon rank sum test, Fisher's exact test, and Pearson's chi squared test were used to assess differences between the groups on six variables of course of illness. RESULTS: Patients with epileptiform discharges or other sharp activity had a history of more hypomanic episodes per year (median (interquartile range (IQR)) 1.5 (3.2) vs. 0.61 (1.1), p = 0.0090) and a higher hypomania:depression ratio (median (IQR) 3.2 (16) vs. 1.0 (1.0), p = 0.00091) as compared to patients without. None of the patients with epileptiform discharges or other sharp activity had self-reported epileptic seizures in their history. CONCLUSIONS: Epileptiform discharges or other sharp activity on EEGs are associated with more hypomanic episodes and an increased hypomania:depression ratio. Our results warrant replication in prospective studies, but suggest that EEG findings could be of prognostic importance for patients diagnosed with bipolar II disorder in psychiatric care. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT00201526 ).

Risk factors of cycle acceleration in acutely admitted patients with bipolar disorder.

OBJECTIVE: 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. RESULTS: 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). CONCLUSION: 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.