Treatment Failure With a Tricyclic Antidepressant Followed by Lithium Addition and Response to Subsequent Electroconvulsive Therapy

Objective: To examine the predictive value of resistance to a tricyclic antidepressant (TCA) and lithium with respect to the efficacy of subsequent electroconvulsive therapy (ECT).

Method: This open prospective study was conducted in the inpatient depression unit of a university hospital in The Netherlands. Patients were enrolled in the study from October 1996 to June 2002 and had to meet DSM-IV criteria for major depressive disorder. Eighty-six patients were treated twice weekly with ECT until recovery or no progress during at least 10 bilateral treatments. Patients were maintained drug free during the ECT treatment. Clinical evaluation of depressive symptoms was performed each week; scores on the 17-item version of the Hamilton Rating Scale for Depression (HAM-D) were obtained 1 to 3 days prior to ECT and 1 to 3 days after treatment termination. The primary outcome criterion was defined as the mean difference in HAM-D score before and after ECT for patients who had received adequate treatment with a TCA and lithium compared with patients who had not received adequate treatment with a TCA and lithium. Adequate treatment was defined as 4 weeks taking a predefined plasma level of a TCA; nonresponders had lithium added to the medication, and the minimal duration of the lithium addition was 3 weeks with a plasma level of at least 0.6 mmol/L. Independent samples t test was used to analyze this primary outcome criterion.

Results: According to the primary outcome criterion, patients who had received adequate treatment with a TCA and lithium (N = 56) had a mean difference in HAM-D score pre-ECT and post-ECT of 16.4 compared to a HAM-D score difference of 19.5 in the patient group who had received inadequate treatment with a TCA and lithium (N = 30). This inequality in differences in mean HAM-D scores is not significant (p = .2).

Conclusion: In the present study sample, treatment failure with adequate pharmacotherapy with a TCA and lithium addition appears to be unrelated to outcome following subsequent ECT.