In this study, 990 patients treated with ECT for major depression or schizoaffective disorder, depressed type between January 1, 2008 and December 31, 2010 in eight hospitals in the middle of Sweden were identified. Information about the clinical outcome was available for 936 patients. Our data therefore illustrate a population-based cohort treated in ordinary clinical routine.
Inclusion criteria in the study were:
1) Diagnosis of Depressive Episode (F32), Major Depressive Disorder (F33) Bipolar Disorder, depressive episode (F31.3-F31.5) or Schizoaffective disorder, depressive type (F25.1).
2) Treatment with ECT in one of the eight hospitals in the middle of Sweden between January 1, 2008 and December 31, 2010. Each patient was included only with the first treatment series in the period.
Exclusion criteria from statistical analysis was:
1) No Clinical Global Impression – Improvement (CGI-I) data available after ECT.
Included and excluded subjects
Out of 990 patients treated with ECT during the period, 54 patients were excluded from the response analysis because no CGI-I data were available after ECT. Patients with and without CGI-I ratings after ECT were similar as concerns age 54
years (SD 18) vs 53 (SD 16), sex (57% vs 61% women), diagnoses (76% vs 79% unipolar depression, 19% vs 17% bipolar depression and 5% vs 4% schizoaffective disorder depressed type). The severity of depression among patients with and without CGI-I ratings were mild/moderate 32% vs 37%, severe without psychosis 47% vs 44% and severe with psychosis 25% vs 16%. The proportion of diagnosed co-morbid personality disorders were 8% among CGI-I rated patients vs 11% for patients without CGI-I rating. 19% of the patients with CGI-I ratings were outpatients vs 28% for patients without the ratings. The number of ECT sessions given for patients with CGI-I ratings was 8.0 (SD 3.2) vs. 7.2 (SD 3.7) for patients not rated.
The Quality register
The data in this study were derived from the Quality register for ECT. Nurses at each site collected information from the patients’ charts. In Sweden, all ECTs are provided in psychiatric hospitals responsible for the treatment of all patients in a defined geographical area. Eight hospitals in the middle of Sweden collaborated in 2008–2010 to report clinical data to the register. The eight hospitals cover a population of 1.5 million inhabitants. Six hospitals started reporting data in 2008, one hospital started in 2009 and one hospital in 2010.
The Regional Ethical Vetting Board in Uppsala approved the study. The patients were informed about the register and accepted registration.
ECT was administered using a bidirectional constant current, brief pulse device. The Mecta Spectrum 5000Q device (Mecta Corp, Lake Oswego, Ore) was used at six hospitals and a Thymatron system IV and a Thymatron DGX device (Somatics, Inc, Lake Bluff, Ill) was used at one hospital each.
Most treatments were unilateral, but in 13% at least one of the treatments in the series was bitemporal and in 4.8% at least one treatment was bifrontal. The mean dosage at the last treatment if unilateral was 0.49
ms (SD 0.14), 73
Hz (SD 23), 7.4
s (SD 0.83), 840 (SD 53) mA and 451 (SD 186) mC. The mean number of ECT sessions was 8.0 (SD 3.2).
Propofol (mean dosage 107
mg (SD 41) or thiopental (mean dosage 306
mg (SD 98)) was used as anaesthetic. Succinylcholine (1
mg/kg) was used as muscle relaxant and glycopyrrolate (0.2
mg) was used as anticholinergic. If no adverse events occurred, ECT was continued until the patients were asymptomatic or the physician judged that the patient had benefitted as much as possible.
The pharmacotherapy was assessed at the conclusion of the ECT series. An antidepressant drug was used by 87% of the patients. Selective Serotonin Reuptake Inhibitors were used by 36% of the patients, Serotonin–norepinephrine reuptake inhibitors by 22%, mirtazapine by 25%, tricyclics by 7%, other antidepressants by 19%, lithium by 16%, lamotrigine by 10%, valproate by 3%, benzodiazepines by 24%, other antiepileptic drugs by 9% and antipsychotics by 39%. Specific psychotherapy was seldom used but supportive care was provided. The supportive care was more intensive for inpatients.
Variables and measures
The Clinical Global Impression – Improvement scale (CGI-I) [16
] is a scale ranging from 1
very much improved, 2
much improved, 3
minimally improved and 4
not improved. Experienced nurses who met the patients during the ECT sessions made the ratings. The CGI-I rating was performed within one week after ECT. When the nurses made the ratings, they had access to the charts including the doctors’ professional assessments and the patients’ self-assessments used in the routine care. In the analysis, CGI-I 1 or 2 was considered improved and 3 or 4 was considered not improved.
The severity of depression was assessed by the treating physician according to the International Classification of Diagnosis 10th version (ICD) as mild/moderate, severe without psychosis or severe with psychosis. A corresponding severity classification was used in schizoaffective disorders, depressed type.
The outpatients were those with at least one ECT administered in an outpatient setting. Thus if the treatment was initiated in an inpatient setting and continued in an outpatient setting the patient was considered to be an outpatient in the statistical analysis.
The voluntary/involuntary hospital admission status variable was based on the legal status of the patient. In Sweden, verbal consent to ECT is standard and the treating physician can administer ECT without consent during involuntary care. Some voluntarily hospitalised patients may recognise that they have to accept ECT or else risk involuntary care. Some involuntarily hospitalised patients may consent to ECT.
Validation of measures
In 524 patients CGI-I improvement could be compared to the pre to post ECT change in Global assessment of functioning – symptoms score (GAF-S). Patients improved according to CGI-I increased their GAF-S by 26 (SD 13) while those not improved increased their GAF-S score by 8 (SD 8). In 80 patients pre to post ECT change in Montgomery Åsberg Depression Rating Scale (MADRS) was available. Improved patients decreased MADRS by 26.6 (SD 12.5) and not improved by 6 (11.1). Change in Montgomery Åsberg Depression Rating Scale –Self Assessment (MADRS-SA) was available in 349 cases. Improved patients decreased MADRS-SA by 23.2 (SD 9.7) and not improved by 10.1 (SD 10.0). All measures were recorded within one week before ECT and within week after ECT. The nurses were trained to assess Clinical Global Impression-Improvement, but the inter-rater reliability was not investigated.
The severity classification according to ICD was compared to the Clinical Global Impression –Severity (CGI-S) score before ECT in 867 patients. CGI-S was assessed by the physician who referred the patient for ECT. On CGI-S patients classified as mild/moderately depressed were scored 4.2 (SD 0.6), severe without psychosis 5.2 (SD 0.7) and severe with psychosis 5.7 (SD 0.6). GAF-S scores before ECT was available in 601 cases. GAF-S scores were, mild/moderately depressed patients 44 (SD 10), severe without psychosis 39 (SD 11), severe with psychosis 33 (SD 11). MADRS scores amongst 151 patients before ECT were for mild/moderately depressed 30.3 (SD 8.6), severe depression without psychosis 34.0 (SD 6.8), severe depression with psychosis 36.4 (SD 7.9). MADRS-S scores amongst 465 patients before ECT were for mild/moderately depressed 31.7 (SD 7.9), for severely depressed patients without psychosis 35.5 (SD 7.4) and for patients with severe depression with psychosis 33.4 (SD 9.5).
Frequency distributions were tested by means of chi-square tests. Differences between means were tested by the Student's t-test.
To assess the relative importance of certain factors, a logistic regression, forward conditional, with improved as dependent variable and factors with a trend toward statistical significance in the univariate analysis entered (p
The tests performed were two sided and alpha was set to 0.05. SPSS version 15.0 (SPSS Inc, Chicago, Ill) was used for the statistical analyses.