Background: Because randomized clinical trials in bipolar disorder include restricted study populations, the possibilities for generalizing to real-world bipolar patients are limited. Naturalistic long-term data can add valuable information about the diversity of treatment and outcome in bipolar disorder.
Method: After discharge from a psychiatric community hospital, 300 consecutively admitted patients with ICD-10 bipolar I (n = 158) and II (n = 142) disorder were followed up naturalistically for 4 years. Patients were assessed with regard to time to relapse, relapse polarity in relation to index episode, prophylactic effects of prescribed medication, prescribing behaviors, and medication adherence. Drugs were chosen by the treating psychiatrists on the basis of clinical judgment. Prescribed medications included lithium, carbamazepine, valproate, lamotrigine, antidepressants, and atypical antipsychotics, all of which were compared as a single mood stabilizer or in combination with at least 2 prophylactic agents. The study was conducted from 2000 through 2008.
Results: 204 of 300 patients (68%) relapsed within 4 years, with a mean of 208 days (SD = 356.2) until the next affective episode. Relapses correlated in a statistically significant manner with the index episode (χ²₄ = 57.48, P = .000; bipolar I: χ²₄ = 20.19, P = .000; bipolar II: χ²₄ = 106.82, P = .000). A Kaplan survival analysis showed that lithium in monotherapy statistically significantly delayed time to the next affective relapse (P = .002). Survival (time to relapse) was also statistically significantly reduced when prophylactic medication was changed by the psychiatrist (P = .000) or stopped by the patient (P = .001). In general, no differences in tested parameters were seen between the bipolar I and II groups.
Conclusions: Our data confirm a high risk of relapse in a naturalistic setting. Lithium seems to offer some advantage over other medication over the long-term treatment of bipolar I and II disorder. Patients tend to relapse with the same polarity as their index episode; this emphasizes the importance of the polarity concept. Changing of medications by the psychiatrist and stopping of medication by the patient appear to be risk factors for an earlier affective relapse.
Trial registration: ClinicalTrials.gov identifier: NCT01792128.
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