Bipolar mixed states were systematically described for the first time by Emil Kraepelin. Since then, their high prevalence has been repeatedly recognized, but they still remain poorly understood. These patients appear to be extremely difficult to treat, many being refractory to pharmacological approaches. Clinical experience supports the use of electroconvulsive therapy (ECT) in mixed states, but there is little information on its effectiveness in scientific literature.

Report our experience in using acute phase ECT (aECT) in mixed states.

The authors reviewed the clinical records of all patients submitted to aECT between June 2006 and June 2011. The inclusion criteria were: a) presence of a mixed state according to Akiskal's criteria (Akiskal et al,2005); b) completed treatment course with aECT. The following variables were collected: demographic characteristics, previous response to pharmacotherapy, presence of psychotic symptoms, number of aECT sessions, referral to continuation or maintenance ECT (c/mECT), number of readmissions. Relation between the diagnostics and the number of ECT sessions was validated with Eta-coefficient. Comparison between these two groups was carried out with One-Way-ANOVA.

Eighteen patients met inclusion criteria and were resistant to pharmacotherapy. Eight patients had psychotic features. All patients but one showed a positive clinical response, as documented on CGI. The average number of ECT sessions was five, while the mean of ECT treatments in manic and depressive patients was seven and six respectively. Thirteen patients were scheduled for c/mECT.

Our results confirm the effectiveness of ECT in medication nonresponsive patients experiencing a mixed state.