ECT in bipolar and unipolar depression: differences in speed of response

Objectives: There is sparse evidence for differences in response to electroconvulsive therapy (ECT) between patients with bipolar or unipolar major depression, with virtually no information on speed of response. We contrasted a large sample of bipolar (BP) and unipolar (UP) depressed patients in likelihood and rapidity of clinical improvement with ECT. Methods: Over three double-blind treatment protocols, 228 patients met Research Diagnostic Criteria for UP (n=162) or BP depression (n=66). Other than lorazepam PRN (3 mg/day), patients were withdrawn from psychotropics prior to the ECT course and until after post-ECT assessments. Patients were randomized to ECT conditions that differed in electrode placement and stimulus intensity. Symptomatic change was evaluated at least twice weekly by a blinded evaluation team, which also determined treatment length. Results: Patients with BP and UP depression did not differ in rates of response or remission following the ECT course, or in response to unilateral or bilateral ECT. Degree of improvement in Hamilton Rating Scale for Depression scores following completion of ECT was also comparable. However, BP patients received significantly fewer ECT treatments than UP patients, and this effect was especially marked among bipolar ECT responders. Both BP I and BP II patients showed especially rapid response to ECT. Conclusions: The BP/UP distinction had no predictive value in determining ECT outcome. In contrast, there was a large effect for BP patients to show more rapid clinical improvement and require fewer treatments than unipolar patients. The reasons for this difference are unknown, but could reflect a more rapid build up of anticonvulsant effects in BP patients.     

Bifrontal versus right unilateral and bitemporal electroconvulsive therapy in major depressive disorder

OBJECTIVES: We sought to evaluate the safety and efficacy of three electroconvulsive therapy (ECT) methods: moderate-dose bifrontal, low-dose bitemporal, and high-dose right unilateral in the treatment of a major depressive episode. METHODS: In an 8-session, double-blinded parallel group study, 45 consecutive depressive patients who were referred for ECT to Noor Hospital were assigned randomly to bifrontal, moderate dose (50% above seizure threshold; n = 15); bitemporal, low dose (just above seizure threshold; n = 15); and right unilateral, high dose (400% above the seizure threshold; n = 15) ECT applications. Primary outcome measures included assessment by Mini-Mental State Examination and Hamilton Depression Rating Scale. RESULTS: Thirty-nine of the patients completed the course of treatment. Two patients in bifrontal, 1 in bitemporal, and 3 in right unilateral dropped out of the study. The 3 groups did not show any difference in baseline characteristics. There was a significant difference between standardized Mini-Mental State scores of patients in bifrontal group compared with bitemporal and right unilateral patients (P < 0.05). The effectiveness of the 3 ECT methods, assessed by Hamilton Depression Rating Scale, did not show any significant difference (P > 0.05). CONCLUSION: Moderate-dose bifrontal ECT revealed fewer cognitive side effects in comparison with bitemporal and right unilateral. Moderate-dose bifrontal ECT had the same efficacy compared with low-dose bitemporal and high-dose right unilateral in the treatment of depression.     

Right unilateral and bifrontal electroconvulsive therapy in the treatment of depression: a preliminary study

The short-term outcome of electroconvulsive therapy (ECT) was studied in 24 patients with a current major depressive episode (DSM-IV). Patients were randomized to high dose (400% above the seizure threshold) right unilateral (RUL) ECT, to moderate dose (150% above seizure threshold) RUL ECT, and to low dose (just above seizure threshold) bifrontal (BF) ECT. Primary outcome measures included number of treatments, Hamilton Depression Rating Scale score, and Mini-Mental State Examination score. High dose RUL ECT was associated with a significantly faster response to treatment than low dose BF ECT. Moreover, there was a tendency to a higher response rate with high dose RUL ECT compared with either moderate dose RUL ECT or BF ECT.     

Comparison of bifrontal and bitemporal ECT for major depression

OBJECTIVE: The authors compared the clinical and cognitive effects of bifrontal electrode placement with standard bitemporal electrode placement in the treatment of patients with major depression. METHOD: Forty-eight patients with unipolar or bipolar depression were treated with a course of bifrontal or bitemporal ECT. The Hamilton Rating Scale for Depression and the standardized Mini-Mental State were administered at baseline and repeated during the course of treatment. RESULTS: Forty-seven of the 48 patients who completed the course of treatment met remission criteria by the 12th treatment. There were no differences between the patients given bifrontal ECT and those given bitemporal ECT in the number of treatments required to reach remission criteria. The standardized Mini-Mental State scores of the patients given bitemporal ECT worsened more after treatment than did those of the patients given bifrontal ECT. CONCLUSIONS: Bifrontal electrode placement was as efficacious as bitemporal placement and resulted in less cognitive impairment. A study of the two placements with more cognitive measures is indicated.     

Electroconvulsive therapy is equally effective in unipolar and bipolar depression

Bailine S, Fink M, Knapp R, Petrides G, Husain MM, Rasmussen K, Sampson S, Mueller M, McClintock SM, Tobias KG, Kellner CH. Electroconvulsive therapy is equally effective in unipolar and bipolar depression. Objective: To determine the relative efficacy of electroconvulsive therapy (ECT) in the treatment of bipolar (BP) and unipolar (UP) depressive illness and clarify its role in BP depression. Method: Patients referred for ECT with both UP and BP depressions. [classified by Structured Clinical Interview for DSM (SCID‐I) criteria for history of mania] were included in a multi‐site collaborative, double‐masked, randomized controlled trial of three electrode placements – right unilateral, bifrontal or bitemporal – in a permutated block randomization scheme. Results: Of 220 patients, 170 patients (77.3%) were classified as UP and 50 (22.7%) as BP depression in the intent‐to‐treat sample. The remission and response rates and numbers of ECT for both groups were equivalent. Conclusion: Both UP and BP depressions remit with ECT. Polarity is not a factor in the response rate. In this sample ECT did not precipitate mania in depressed patients. Treatment algorithms for UP and BP depression warrant re‐evaluation.     

Double-blind randomized controlled study comparing short-term efficacy of bifrontal and bitemporal electroconvulsive therapy in acute mania

Background:  Bifrontal electrode placement is as efficacious as bitemporal placement during electroconvulsive therapy (ECT) in depression but is associated with fewer cognitive adverse effects. There are no studies comparing these techniques in acute mania. This study compared the short-term efficacy and adverse effects of bifrontal and bitemporal ECT in the treatment of acute mania.
Method:  Thirty-six DSM-IV mania inpatients referred for ECT were recruited for study. They were randomized to receive bifrontal (BFECT; n = 17) or bitemporal (BTECT; n = 19) ECT. None of the subjects were on mood stabilizers during the course of ECT. Severity of mania was measured on the Young Mania Rating Scale (YMRS) before beginning ECT and then on Days 3, 7, 11, 14, and 21 of treatment. Cognitive functions were assessed eight hours after the fifth ECT session using the Mini-Mental Status Examination (MMSE), Paired Associate Learning Test, Complex Figure Test, Verbal Fluency Test (animals and fruits categories), and Trail Making Test, Part A.
Results:  The subjects in the two groups were comparable on sociodemographic and clinical variables, including severity of mania at baseline. They were also similar in ECT parameters, including seizure threshold and seizure duration. Mean YMRS scores showed faster decline in the BFECT than in the BTECT group. Kaplan–Meier survival analysis showed that a greater proportion of subjects in the BFECT group responded (50% reduction in YMRS score) significantly earlier than in the BTECT group. There were no significant differences between the groups in performance on cognitive function tests.
Conclusion:  In this pilot study, mania patients treated with BFECT responded faster than those treated with BTECT, with comparable cognitive adverse effects. Since ECT is usually prescribed for rapid control of symptoms, BFECT may be preferred over BTECT in the treatment of acute mania.     

Creatine monohydrate in resistant depression: a preliminary study

OBJECTIVES: Creatine plays a pivotal role in brain energy homeostasis, and altered cerebral energy metabolism may be involved in the pathophysiology of depression. Oral creatine supplementation may modify brain high-energy phosphate metabolism in depressed subjects. METHODS: Eight unipolar and two bipolar patients with treatment-resistant depression were treated for four weeks with 3-5 g/day of creatine monohydrate in an open add-on design. Outcome measures were the Hamilton Depression Rating Scale, Hamilton Anxiety Scale, and Clinical Global Impression scores, recorded at baseline and at weeks 1, 2, 3 and 4. RESULTS: One patient improved considerably after one week and withdrew. Both bipolar patients developed hypomania/mania. For the remaining seven patients, all scale scores significantly improved. Adverse reactions were mild and transitory. CONCLUSIONS: This small, preliminary, open study of creatine monohydrate suggests a beneficial effect of creatine augmentation in unipolar depression, but possible precipitation of a manic switch in bipolar depression.     

Gabapentin augmentation therapy in bipolar depression

Background:  Gabapentin (GBP) may be useful in bipolar disorders, including as adjunctive therapy for bipolar depression, although controlled studies suggest inefficacy as primary treatment for mania or treatment-resistant rapid cycling.
Methods:  We performed a 12-week trial of open GBP (mean dose 1725 mg/day) added to stable doses of mood stabilizers or atypical antipsychotics in 22 (10 women, mean age 38.4 years) depressed [28-item Hamilton Depression Rating Scale (HDRS) >18] bipolar (10 bipolar I, 12 bipolar II) disorder outpatients. Mean illness duration was 18.6 years; current depressive episode duration was 18.0 weeks. Prospective 28-item HDRS, Young Mania Rating Scale (YMRS) and Clinical Global Impression – Severity (CGI-S) ratings were obtained.
Results:  Overall, HDRS ratings decreased 53% from 32.5 ± 7.7 at baseline to 16.5 ± 12.8 at week 12 (p < 0.0001). Twelve of 22 (55%) patients had moderate to marked improvement (HDRS decrease=50%) with HDRS decreasing 78% from 27.9 ± 6.2 to 6.2 ± 4.5 (p < 0.0001). Eight of 22 (36%) patients remitted (HDRS≥8). In non-responders, HDRS decreased from 38.0 ± 5.4 to 28.9 ± 6.7 (p=0.005). Ten of 13 (77%) mild to moderately depressed (baseline HDRS >18 and <35) patients responded, while only two of nine patients (22%) with severe depression (HDRS ≥ 35) responded (p < 0.03). Both groups, however, had similar, statistically significant HDRS decreases. GBP was well tolerated.
Conclusion:  Open adjunctive GBP was effective and well tolerated in patients with mild to moderate bipolar depression. This open pilot study must be viewed with caution, and randomized controlled studies are warranted.     

Gabapentin in the acute treatment of refractory bipolar disorder

Background: Gabapentin, a new anti-epileptic agent, has been anecdotally reported to be effective in the treatment of mania. We systematically assessed the response rate in bipolar patients being treated adjunctively with gabapentin for manic symptoms, depressive symptoms, or rapid cycling not responsive to standard treatments.
Method: Twenty-eight bipolar patients experiencing manic (n=18), depressive (n=5), or rapid-cycling (n=5) symptoms inadequately responsive to at least one mood stabilizer were treated in an open fashion with adjunctive gabapentin. Illness response was assessed using the Clinical Global Impression Scale modified for bipolar disorder (CGI-BP). A 'positive response' was operationalized as a CGI response of much or very much improved.
Results: Fourteen of the 18 (78%) treated for hypomania or mania had a positive response to a dosage range of 600–3600 mg/day. Patients with hypomania responded fastest, with a positive response achieved in 12.7±7.2 days. Patients with classic mania had a mean time to positive response of 25±12 days, and in patients with mixed mania it was 31.8±20.9 days. All of the five patients treated for depression had a positive response within 21±13.9 days. Only one of five patients with rapid cycling had a positive response. Gabapentin was well tolerated by all patients, with the most common side-effect being sedation.
Conclusions: Gabapentin appears to have acute anti-manic and anti-depressant properties as an adjunctive agent for refractory bipolar illness. Prospective double-blind studies are needed to further delineate its acute efficacy when used as monotherapy and its prophylactic efficacy as monotherapy or in conjuction with other mood stabilizers.     

Augmentative repetitive navigated transcranial magnetic stimulation (rTMS) in drug-resistant bipolar depression

Objectives:  The efficacy of transcranial magnetic stimulation (TMS) has been poorly investigated in bipolar depression. The present study aimed to assess the efficacy of low-frequency repetitive TMS (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) combined with brain navigation in a sample of bipolar depressed subjects.
Methods:  Eleven subjects with bipolar I or bipolar II disorder and major depressive episode who did not respond to previous pharmacological treatment were treated with three weeks of open-label rTMS at 1 Hz, 110% of motor threshold, 300 stimuli/day.
Results:  All subjects completed the trial showing a statistically significant improvement on the 21-item Hamilton Depression Rating Scale (HAM-D), Montgomery-Åsberg Depression Rating Scale, and Clinical Global Impression severity of illness scale (ANOVAs with repeated measures: F  =   22.36, p < 0.0001; F  =   12.66, p < 0.0001; and F  =   10.41, p < 0.0001, respectively). In addition, stimulation response, defined as an endpoint HAM-D score reduction of ≥50% compared to baseline, was achieved by 6 out of 11 subjects, 4 of whom were considered remitters (HAM-D endpoint score ≤ 8). Partial response (endpoint HAM-D score reduction between 25% and 50%) was achieved by 3/11 patients. No manic/hypomanic activation was detected during the treatment according to Young Mania Rating Scale scores (ANOVAs with repeated measures: F  =   0.62, p = 0.61). Side effects were slight and were limited to the first days of treatment.
Conclusions:  Augmentative low-frequency rTMS of the right DLPFC combined with brain navigation was effective and well tolerated in a small sample of drug-resistant bipolar depressive patients, even though the lack of a sham controlled group limits confidence in the results.     

Repetitive transcranial magnetic stimulation versus electroconvulsive therapy for major depression: preliminary results of a randomized trial.

BACKGROUND: Many severely depressed patients do not benefit from or tolerate existing treatments. Repetitive transcranial magnetic stimulation (rTMS) has been reported to benefit depression. We compared rTMS to electroconvulsive therapy (ECT) in severely ill, depressed patients. METHODS: Twenty-five patients with a major depression (unipolar or bipolar) deemed clinically appropriate for ECT were randomly assigned to rTMS (10-20 treatments, 10 Hz, 110% motor threshold applied to the left dorsolateral prefrontal cortex for a total of 10,000-20,000 stimulations) or a course of bitemporal ECT (4-12 treatments). The primary outcome measure was the 24-item Hamilton Depression Rating Scale (HDRS). The Brief Psychiatric Rating Scale (BPRS), Young Mania Rating Scale (YMS), and Clinical Global Impression scale (CGI) were secondary measures. Minimal rescue medications were utilized. RESULTS: Mean percent improvement on the baseline HDRS score did not significantly differ between the two treatments (i.e., 55% for the rTMS group vs. 64% for the ECT group [p = ns]). With response defined as a 50% reduction from baseline and a final score < or = 8 on the HDRS, there was also no significant difference between the two groups. We did not observe any differences between groups on the secondary measures. CONCLUSIONS: A 2-4 week randomized, prospective trial comparing rTMS to ECT produced comparable therapeutic effects in severely depressed patients.     

Risperidone in the treatment of mixed state bipolar patients: Results from a 24-week, multicenter, open-label study in Korea

Aims:  The goal of the present study was to evaluate the efficacy of risperidone combined with mood stabilizers for treating bipolar mixed state.
Methods:  The present study was a 24-week, open-label, combination, prospective investigation of the efficacy of risperidone in combination with mood stabilizers. Risperidone (1–6 mg/day) was given in combination with mood stabilizers in flexible doses according to clinical response and tolerability for 114 patients in mixed or manic episode.
Results:  Forty-four patients met our criteria for mixed state bipolar disorder and 70 met the criteria for pure mania. Mean age for the subjects was 39.0 ± 11.0 years and 55.3% were female. The combination of risperidone with mood stabilizers significantly improved the scores on the Young Mania Rating Scale (YMRS), 17-item Hamilton Rating Scale for Depression (HAMD), 18-item Brief Psychiatric Rating Scale (BPRS), Global Assessment Scale (GAS), and Clinical Global Impression Scale for use in bipolar illness Severity (CGI-BP) at 24 weeks ( P  < 0.0001). Analysis of the YMRS, BPRS, GAS, and CGI-BP scores showed significant improvement in both the manic and mixed groups. The rate of response in YMRS scores was 84.2% ( n  = 96) and the rate of YMRS remission was 77.2% ( n  = 88) at week 24 in the total population. Seventy-four patients met both YMRS ≤ 12 and HAMD ≤ 7 at week 24 (64.9%). Risperidone was well tolerated, and adverse events were mostly mild.
Conclusion:  The combination of risperidone with mood stabilizers was an effective and safe treatment for manic symptoms and coexisting depressive symptoms of bipolar disorder.     

Olanzapine in diverse syndromal and subsyndromal exacerbations of bipolar disorders

Objective:  To evaluate effects of olanzapine in diverse exacerbations of bipolar disorders.
Methods:  Twenty-five evaluable bipolar disorder [14 bipolar I (BPI), 10 bipolar II (BPII) and one bipolar disorder not otherwise specified (BP NOS)] outpatients received open olanzapine (15 adjunctive, 10 monotherapy). Thirteen had elevated (11 syndromal, two subsyndromal) and 12 depressed (four syndromal, eight subsyndromal) mood symptoms of at least mild severity, with Clinical Global Impression-Severity (CGI-S) scores of at least 3. Only one had psychotic symptoms.
Results:  With open olanzapine (15 adjunctive, 10 monotherapy), overall symptom severity (CGI-S) as well as mood elevation (Young Mania Rating Scale), depression (Hamilton and Montgomery-Asberg Depression Rating Scales), and anxiety (Hamilton Anxiety Rating Scale), rapidly decreased (significantly by days 2–3). Patients with the greatest baseline severity (CGI-S) had the greatest improvement. Fifteen of 25 (60%) patients responded. Time to consistent response was bimodal, with five early (by 0.5 ± 0.3 weeks) and 10 late (by 7.0 ± 1.9 weeks) responders. Early compared with late responders had 51% lower final olanzapine doses. Olanzapine was generally well tolerated, with sedation and weight gain the most common adverse effects.
Conclusions:  Olanzapine was effective in diverse exacerbations of bipolar disorders. The bimodal distribution of time to response and different final doses are consistent with differential mechanisms mediating early compared with late responses. Controlled studies are warranted to further explore these preliminary observations.     

A review of antidepressant-induced hypomania in major depression: suggestions for DSM-V

Objectives:  To determine if the classification of 'antidepressant-induced hypomania' in DSM-IV is supported by available data.
Methods:  We reviewed the available scientific literature to examine the incidence of mania and hypomania in non-bipolar patients who were treated with antidepressants.
Results:  Eighty-nine per cent of studies of antidepressants in major depressive disorder patients reported no cases of treatment-induced hypomania. No instances of treatment-induced hypomania were reported in three large studies of patients with chronic forms of depression.
Conclusions:  The rate of antidepressant-induced hypomania in major depressive disorder is within the rate of misdiagnosis of bipolar depression as unipolar. Depressed patients who experience antidepressant-associated hypomania are truly bipolar.     

Oxcarbazepine add-on in the treatment of refractory bipolar disorder

Objective:  To assess the effectiveness and safety of oxcarbazepine (OXC) in bipolar disorder (BD) and related conditions.
Methods:  We reviewed medical records of patients given OXC treatment between March 2003 and March 2005 at the University of British Columbia Hospital. Response to treatment was assessed retrospectively using the Clinical Global Impression of Severity (CGI-S), and the Clinical Global Impression of Improvement (CGI-I) scales.
Results:  OXC was prescribed to 15 patients with bipolar I (n = 12), bipolar II (n = 2) and schizoaffective (n = 1) disorder who presented with depression (n = 9), mania (n = 3), hypomania (n = 1), or mixed state (n = 2). Six patients had Axis II diagnoses and 10 patients had a family history of mood disorders. Psychiatric co-morbidity was found in four patients. The mean daily dose of OXC was 775 ± 556.11 mg/day and the mean duration of follow-up was 31.60 ± 41.51 weeks. The OXC add-on led to a significant reduction in symptoms as indicated by reduction in CGI-S scores at 1 and 2 months. Nine of 12 patients at 1 month and seven of 14 at 1 or 2 months were much or very much improved on CGI-I scale. One patient (7%) developed hyponatremia. Six patients (40%) experienced no side effects and three patients (20%) stopped the medication because of side effects.
Conclusion:  OXC was effective and well-tolerated in refractory BD and schizoaffective disorder. These preliminary data are promising but controlled studies are needed to confirm its efficacy in refractory BD.     

ECT remission rates in psychotic versus nonpsychotic depressed patients: a report from CORE.

OBJECTIVE: To compare the relative efficacy of electroconvulsive therapy (ECT) in psychotic and nonpsychotic patients with unipolar major depression. METHODS: The outcome of an acute ECT course in 253 patients with nonpsychotic (n = 176) and psychotic (n = 77) unipolar major depression was assessed in the first phase of an ongoing National Institute of Mental Health-supported four-hospital collaborative study of continuation treatments after successful ECT courses. ECT was administered with bilateral electrode placement at 50% above the titrated seizure threshold. The remission criteria were rigorous: a score 相似文献   

Depression with DSM-IV atypical features: a marker for bipolar II disorder

The aim of the study was to find the prevalence of atypical features in bipolar II depression versus unipolar depression. Five hundred and fifty seven unipolar and bipolar II depressed outpatients were interviewed with the Structured Clinical Interview for DSM-IV, the Montgomery Asberg Depression Rating Scale, and the Global Assessment of Functioning Scale. DSM-IV atypical features were significantly more common in bipolar II patients than in unipolar patients (45.4% vs 25.4%, odds ratio 2.4). As the diagnosis of bipolar II disorder is often based on diagnosis of past hypomania, which may not be very reliable, depression with atypical features may point to bipolar II disorder diagnosis. Received: 18 February 1999 / Accepted: 29 October 1999     

Differential item functioning of DSM-IV depressive symptoms in individuals with a history of mania versus those without: an item response theory analysis

Objectives:  Although major depression is characteristic of both bipolar disorder and major depressive disorder, there is disagreement as to whether there are distinct features of depression that differentiate these two conditions. The primary aim of this study was to use methods based in item response theory to evaluate differences in DSM-IV depression symptom endorsement in an epidemiological sample of individuals with a history of mania (i.e., bipolar depression) versus those without (i.e., unipolar depression).
Methods:  Clinical interview data were drawn from a subsample (n = 13,058) of individuals with bipolar or unipolar depression who had participated in the National Epidemiologic Survey on Alcohol and Related Conditions. Using these data, a two-parameter item response model was used to estimate differential item functioning of DSM-IV depressive symptoms between these two groups.
Results:  Differences in severity parameter estimates revealed that suicidal ideation and psychomotor disturbance were more likely to be endorsed across most levels of depression severity in bipolar versus unipolar depression. Differences in discrimination parameter estimates revealed that fatigue was significantly less discriminating in bipolar versus unipolar depression.
Conclusions:  Equating for level of depression symptom severity, study results revealed that suicidal ideation and psychomotor disturbance are endorsed more frequently in bipolar versus unipolar depression. Study data also suggested that fatigue may be endorsed more frequently in unipolar relative to bipolar samples at moderate (versus low or high) levels of depression symptom severity.     

Prevalence of bipolar II disorder in atypical depression

The diagnostic validity of atypical depression is based on its superior response to monoamine oxidase inhibitors compared to tricyclic antidepressants, and on latent class analysis. The studies on atypical depression have often not included bipolar patients. The aim of the present study was to find the prevalence of bipolar II disorder among DSM-IV atypical depression outpatients. Bipolar II and unipolar atypical depressions were also compared to find if they were variants of the same disorder or if instead they were different disorders. One hundred and forty consecutive unipolar and bipolar II outpatients, presenting for treatment of an atypical major depressive episode, were interviewed with the Structured Clinical Interview for DSM-IV, the Montgomery Asberg Depression Rating Scale (MADRS), and the Global Assessment of Functioning Scale. The prevalence of bipolar II disorder was 64.2%. The age at baseline and onset were significantly lower in bipolar II versus unipolar patients. All the other variables (MADRS items, duration of illness, severity, gender, psychosis, comorbidity, chronicity, recurrences) were not significantly different. The prevalence of bipolar II disorder among atypical depressed outpatients was higher than previously reported. Received: 27 July 1998 / Accepted: 19 January 1999     

Efficacy of electroconvulsive therapy in bipolar versus unipolar major depression: a meta-analysis

Dierckx B, Heijnen WT, van den Broek WW, Birkenhäger TK. Efficacy of electroconvulsive therapy in bipolar versus unipolar major depression: a meta‐analysis. Bipolar Disord 2012: 14: 146–150. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective: Bipolar major depression differs considerably from unipolar major depression with regard to the efficacy of treatment with antidepressants. In bipolar depression, response to treatment with antidepressants is disappointing. Whether response to electroconvulsive therapy (ECT) differs between bipolar and unipolar depression remains unclear. Therefore, this systematic review investigates the relative efficacy of ECT in both forms of depression. Methods: Relevant cohort studies were identified from a systematic search of the PubMed electronic database. Six studies were included in this meta‐analysis. Results: In this meta‐analysis, the overall remission rate was 50.9% (n = 402/790) for patients with unipolar depression and 53.2% (n = 168/316) for patients with bipolar major depression. A pooled odds ratio (OR) and confidence interval (CI) were calculated using random‐effects meta‐analysis with the Mantel–Haenzel method. This analysis shows similar efficacy of ECT in patients with unipolar and bipolar depression (OR = 1.08, 95% CI: 0.75–1.57). Conclusion: ECT appears to be equally effective for both bipolar and unipolar depression and the remission rates are encouraging, especially for bipolar depression.