To Örebro University

Aims This thesis aimed to investigate 1. the effectiveness of electroconvulsivetherapy (ECT) in bipolar depression and mania in real-life settings; 2. the prognostic factors of response to ECT; 3. readmission ratesand risk factors after the acute phase of bipolar disorder; and 4. the association between ECT and readmission rate in mania.

Methods This thesis includes four nationwide register studies. Data came from several national registers linked by personal identity numbers.

Results Response was achieved in 80.2% of ECT-treated patients with bipolardepression and 84.4% of ECT-treated patients with mania. Younger age was associated with a lower response rate to ECT in depressive episodes. Patients aged 16–30 years had a lower chance of responding than patients aged 31–40 years, 61–70, and 71–80 years. Response to ECT in mania was associated with the severity of symptoms. Patients who were markedly ill, severely ill, and among the most extremely ill had a higher chance of responding than patients with mild to moderate illness. Relapse within 3, 6, and 12 months after bipolar depression was reached by 29%, 41%, and 52% of patients, respectively. After manic episodes, 30%, 41%, and 55% of patients were readmitted within 3, 6, and 12 months, respectively. Treatment with ECT was not associated with a longer time to readmission after a manic episode than other treatments.

Conclusions Over 80% of patients with bipolar depression and mania responded to ECT. In depressive episodes, patients at lower ages had a lower chance of achieving response after ECT, and in mania, patients with more severe symptoms had a higher chance of responding to ECT. The readmission rate after both manic and depressive episodes was high. There was no significant difference between time to readmission in patients treated with and without ECT during index admission for mania.