***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: OBJECTIVE To test whether  pre-electroconvulsive therapy ( ECT )  medication resistance is associated with post-ECT  relapse rates . METHOD In a post hoc analysis of data from a large multicenter trial of post-ECT relapse prevention strategies ( conducted from May 1997 to July 2004 ) , we assessed whether response to antidepressant medications prior to  ECT for a unipolar nonpsychotic depressive episode ( DSM-IV ) was associated with differential relapse rates after remission with ECT . Baseline ( i.e. , pre-ECT ) medication use was assessed with the Antidepressant Treatment History Form . Following remission with ECT that was stable for 1 week , patients were r and omly assigned to receive 6 months of treatment with either combination lithium carbonate/nortriptyline or continuation ECT .  Relapse was assessed with the 24-item Hamilton Rating Scale for Depression . There were 146 patients followed in the first week after remission ( termed the interim week in this study ) , and 73 in the r and omized phase of the study . For the purpose s of this trial , medication resistance is defined as not having responded to at least 1 adequate trial of an antidepressant medication before ECT . RESULTS In the first week after acute remission , 9.8 % of patients not having at least 1 antidepressant medication trial met relapse criteria , while 31.4 % of medication-resistant patients met relapse criteria , a difference that was statistically significant ( p = .026 ) . In the r and omized phase of the study , 34.6 % of non-medication-resistant patients relapsed , while 50.0 % of medication-resistant patients relapsed , a difference that was not significant ( p = .434 ) . CONCLUSION We conclude that nonpsychotic patients who had at least 1 adequate antidepressant medication trial before ECT  may be especially prone to early relapse after successful acute remission with ECT BACKGROUND While electroconvulsive therapy ( ECT ) in major depression is effective , cognitive effects limit its use . Reducing the width of the electrical pulse and using the right unilateral electrode placement may decrease adverse cognitive effects , while preserving efficacy . METHODS In a double-masked study , we r and omly assigned 90 depressed patients to right unilateral ECT at 6 times seizure threshold or bilateral ECT at 2.5 times seizure threshold  , using either a traditional brief pulse ( 1.5 ms ) or an ultrabrief pulse ( 0.3 ms ) . Depressive symptoms and cognition were assessed before , during , and immediately , two , and six months after therapy . Patients who responded were followed for a one-year period . RESULTS The final remission rate for ultrabrief bilateral ECT was 35 percent , compared with 73 percent for ultrabrief unilateral ECT , 65 percent for st and ard pulse width bilateral ECT , and 59 percent for st and ard pulse width unilateral ECT ( all P's<0.05 after covariate adjustment ) . The ultrabrief right unilateral group had less severe cognitive side effects than the other 3 groups in virtually all primary outcome measures assessed in the acute postictal period , and during and immediately following therapy . Both the ultrabrief stimulus and right unilateral electrode placement produced less short- and long-term retro grade amnesia . Patients rated their memory deficits as less severe following ultrabrief right unilateral ECT compared to each of the other three conditions ( P<0.001 ) . CONCLUSIONS The use of an ultrabrief stimulus markedly reduces adverse cognitive effects , and when coupled with markedly suprathreshold right unilateral ECT , also preserves efficacy . ( Clinical Trials.gov number , NCT00487500 . ) CONTEXT Electroconvulsive therapy ( ECT ) is the most effective biological treatment for major depression . However , there is little agreement about clinical ly useful predictors of acute ECT outcomes . OBJECTIVE To assess whether age , sex , burden of comorbid physical illness , age at onset , history of recurrence , episode duration , chronic depression or comorbid dysthymia , melancholic features , episode severity , and medication resistance are predictors of remission after an acute course of ECT . DESIGN We performed an analysis using data gathered prospect ively in 328 patients with unipolar major depression ( according to Research Diagnostic Criteria ) treated with ECT .  The study was conducted from 1993 through 1999 . Patients had a pretreatment score of 21 or higher on the 24-item Hamilton Rating Scale for Depression ( HAM-D ) . Treatment history was assessed using the Antidepressant Treatment History Form . Remission was defined as a 24-item HAM-D score of 10 or less and a 60 % or more relative reduction of the HAM-D score . RESULTS On univariate logistic regression , statistically significant predictors of nonremission were chronic depression/dysthymia , medication resistance , longer episode duration , and younger age . On backward elimination logistic regression , only medication resistance ( OR = 1.67 , 95 % CI = 1.05 to 2.67 ) and chronic depression/ dysthymia ( OR = 1.84 , 95 % CI = 1.06 to 3.21 ) were statistically significant predictors of nonremission . CONCLUSIONS In patients with major depression , lower rates of remission after acute ECT are associated with medication resistance and chronicity , but not with age or burden of physical illness 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 ≤10 on the 24-item Hamilton Rating Scale for Depression ( HRSD ) after 2 consecutive treatments , and a decrease of at least 60 % from baseline . Results The overall remission rate was 87 % for study completers . Among these , patients with psychotic depression had a remission rate of 95 % and those with nonpsychotic depression , 83 % . Improvement in symptomatology , measured by the HRSD , was more robust and appeared sooner in the psychotic patients compared with the nonpsychotic patients . Conclusion Bilateral ECT  is effective in relieving severe major depression . Remission rates are higher and occur earlier in psychotic depressed patients than in nonpsychotic depressed patients . These data support the argument that psychotic depression is a distinguishable nosological entity that warrants separate treatment algorithms Abstract : This prospect i ve study assessed the influence of resistance to antidepressant pharmacotherapy on the short-term response to subsequent electroconvulsive therapy ( ECT ) . Previous research has shown that patients with medication resistance were less likely to respond to ECT . This finding may be applicable to the population of depressed in patients in The Netherl and s , where ECT is often preceded by several medication trials . Eighty-five patients ( 61 female and 24 male patients ) with DSM-IV criteria for depressive disorder , both with and without mood congruent psychotic features , were included for analysis . Medication resistance was rated with the Antidepressant Treatment History Form . Medication resistance was predefined in accordance with the previous research in this field . When a reduction of at least 50 % on the 17-item version of the Hamilton Rating Scale for Depression ( HRSD ) between pre- and post-ECT is used as response criterion , medication-resistant patients were equally likely to respond to subsequent ECT ( 30/48 = 82.5 % ) than patients without medication resistance ( 30/37 = 81.1 % ) . Even when post-ECT HRSD score ≤7 was used ( full remission ) , there was no significant difference between medication-resistant patients ( 21/48 = 43.8 % ) and patients without medication resistance ( 15/37 = 40.5 % ) . When potential confounding variables were taken into account , these differences remain nonsignificant . In contrast to earlier research , medication resistance does not influence short-term response to subsequent ECT and it can still be of considerable efficacy CONTEXT Electroconvulsive therapy ( ECT ) is highly effective for treatment of major depression , but naturalistic studies show a high rate of relapse after discontinuation of ECT . OBJECTIVE To determine the efficacy of continuation pharmacotherapy with nortriptyline hydrochloride or combination nortriptyline and lithium carbonate in preventing post-ECT relapse . DESIGN R and omized , double-blind , placebo-controlled trial conducted from 1993 to 1998 , stratified by medication resistance or presence of psychotic depression in the index episode . SETTING Two university-based hospitals and 1 private psychiatric hospital . PATIENTS Of 290 patients with unipolar major depression recruited through clinical referral who completed an open ECT treatment phase , 159 patients met remitter criteria ; 84 remitting patients were eligible and agreed to participate in the continuation study . INTERVENTIONS Patients were r and omly assigned to receive continuation treatment for 24 weeks with placebo ( n = 29 ) , nortriptyline ( target steady-state level , 75 - 125 ng/mL ) ( n = 27 ) , or combination nortriptyline and lithium ( target steady-state level , 0.5 - 0.9 mEq/L ) ( n = 28 ) . MAIN OUTCOME MEASURE Relapse of major depressive episode , compared among the 3 continuation groups . RESULTS Nortriptyline-lithium combination therapy had a marked advantage in time to relapse , superior to both placebo and nortriptyline alone . Over the 24-week trial , the relapse rate for placebo was 84 % ( 95 % confidence interval [ CI ] , 70%-99 % ) ; for nortriptyline , 60 % ( 95 % CI , 41%-79 % ) ; and for nortriptyline-lithium , 39 % ( 95 % CI , 19%-59 % ) . All but 1 instance of relapse with nortriptyline-lithium occurred within 5 weeks of ECT termination , while relapse continued throughout treatment with placebo or nortriptyline alone . Medication-resistant patients , female patients , and those with more severe depressive symptoms following ECT had more rapid relapse . CONCLUSIONS Our study indicates that without active treatment , virtually all remitted patients relapse within 6 months of stopping ECT . Monotherapy with nortriptyline has limited efficacy . The combination of nortriptyline and lithium is more effective , but the relapse rate is still high , particularly during the first month of continuation 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 prospect i ve study was conducted in the inpatient depression unit of a university hospital in The Netherl and s. 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 sample s 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 ine quality 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 BACKGROUND Antidepressant medication resistance is the commonest indication for electroconvulsive therapy ( ECT ) in Scotl and . Evidence from the USA suggests that clinical response is reduced for medication resistant patients . The aim of the present study was to establish if the American results were generalisable to routine clinical practice in Edinburgh . METHOD Fifty eligible depressed patients consecutively referred for a new course of bilateral ECT at the Royal Edinburgh Hospital were prospect ively assessed as part of 
    Output:
    
In conclusion , the efficacy of ECT  is significantly superior in patients without previous pharmacotherapy failure as compared with medication-resistant patients .
Because this finding is based on observational studies , it might be caused by a confounding factor , for example , the presence of psychotic features or the duration of the index episode .
Electroconvulsive therapy seems to be an effective treatment for severely depressed patients as well as for patients with previous pharmacotherapy failure