Efficacy and cognitive effects of right unilateral electroconvulsive therapy

Who is at risk of long-term subjective memory impairment after electroconvulsive therapy?

BACKGROUND

Electroconvulsive therapy (ECT) is an effective treatment for depression with potential transient cognitive side effects. However, subjective memory impairment can extend over a long period after ECT.

OBJECTIVES

This study aimed to assess potential risk factors for long-term subjective memory impairment 6 months after ECT and to explore if the associations are mediated by depressive symptoms.

METHODS

This registry-based study used the Swedish National Quality Register for ECT and other national registers. Long-term subjective memory worsening was defined as a minimum 2-step worsening on the memory item from the comprehensive psychopathological rating scale (CPRS-M) from before ECT to 6 months after ECT. Changes on the scale were also analyzed in continuous models. Statistical methods used were logistic regression and linear regression analyses in univariable and multivariable models.

RESULTS

The study population consisted of 1498 patients. Subjective memory worsening occurred in 25.2 % of the population. Long-term subjective memory worsening was associated with more depressive symptoms and lower education levels. No association could be found related to ECT technical factors. The associations between age and psychiatric comorbidities with subjective memory worsening were mediated by depressive symptoms.

CONCLUSION

Patients can be informed that depressive symptoms are one of the biggest contributing factors to long-term subjective memory impairment after ECT. A successful treatment is therefore important to minimize the long-term experience of memory deficits. The number of sessions or ECT technical factors do not seem to be associated with long-term subjective memory impairment.

Electroconvulsive Therapy Across Nations: A 2022 Survey of Practice

OBJECTIVES

We aimed to characterize worldwide electroconvulsive therapy (ECT) practice and compare practice across nations and global regions.

METHOD

Our anonymous survey was open on SurveyMonkey.com from January to June 2022. We sent invitations to providers identified using a Medicare provider database, an advanced PubMed search function, and professional group listservs. Participants were instructed to submit one survey per ECT site. Response frequencies were pooled by global region and compared using nonparametric methods.

RESULTS

Responses came from 126 sites, mostly in the United States (59%, n = 74), Europe (18%, n = 23), Canada (10%, n = 12), and South/East Asia (6%, n = 8). With some exceptions, sites were broadly consistent in practice as indicated by: a likely shift internationally from bitemporal to right unilateral electrode placement; predominant use of pulse widths <1 ms; preference for seizure threshold titration over age-based dosing methods; widespread availability of continuation/maintenance ECT (97%); and frequent use of quantitative outcome measures for depressive symptoms (88%) and cognitive adverse effects (80%).

CONCLUSIONS

This is the first, published survey that aimed to characterize worldwide ECT practice. With some exceptions, responses suggest a concordance in practice. However, responses were primarily from the Global North. To obtain a truly worldwide characterization of practice, future surveys should include more responses from the Global South.

Effect of Modified Bifrontotemporal Electroconvulsive Therapy on Executive Function in Patients With Psychiatric Illness: A Longitudinal Observational Study

OBJECTIVE

The study was conducted to compare the pre-electroconvulsive therapy (ECT) and post-ECT status of the executive functions of patients and report any deficits found at long-term follow-up. The secondary objective of the study was to compare the performance at executive function tests after ECT with patient characteristics and ECT parameters.

METHODOLOGY

In a prospective longitudinal observational study, 50 patients in the age group of 18 to 65 years who were receiving modified bifrontotemporal ECT for the first time and admitted in psychiatry ward of a tertiary care hospital from July 2015 to June 2016 were assessed for executive functions using a neuropsychological battery consisting of digit span forward, digit span backward, spatial span forward, spatial span backward, phonemic verbal fluency test, semantic verbal fluency test, Stroop test, and Wisconsin Card Sorting Test, a day before ECT and then followed up at 3 and 6 months.

RESULTS

Patients' score improved on all the tests of executive function at 3-month follow-up and was significant for some tests. Improvement was sustained for all the tests 6 months after ECT. Number of years of formal education of patients before illness significantly influenced patients' performance on most of the executive function tests after ECT. Younger age of the patient positively influenced patients' performance on digit span forward and backwards and semantic verbal fluency.

CONCLUSIONS

There are no executive function deficits 3 to 6 months after brief pulse modified ECT with bilateral electrode placement. A higher premorbid education level is associated with better performance on executive functions after ECT.

A critique of narrative reviews of the evidence-base for ECT in depression

There has been recent debate regarding the efficacy of electroconvulsive therapy in the treatment of depression. This has been based on narrative reviews that contradict existing systematic reviews and meta-analyses. In this special article, we highlight the mistakes that occur when interpreting evidence using narrative reviews, as opposed to conventional systematic reviews and meta-analyses.

Confirmatory Efficacy and Safety Trial of Magnetic Seizure Therapy for Depression (CREST-MST): study protocol for a randomized non-inferiority trial of magnetic seizure therapy versus electroconvulsive therapy

BACKGROUND

Electroconvulsive therapy (ECT) is well-established and effective for treatment-resistant depression (TRD), but in Canada and the USA, less than 1% of patients with TRD receive ECT mainly due to its cognitive adverse effects (i.e. amnesia). Thus, new treatment alternatives for TRD are urgently needed. One such treatment is magnetic seizure therapy (MST). ECT involves applying a train of high-frequency electrical stimuli to induce a seizure, whereas MST involves applying a train of high-frequency magnetic stimuli to induce a seizure.

METHODS

In this manuscript, we introduce our international, two-site, double-blinded, randomized, non-inferiority clinical trial to develop MST as an effective and safe treatment for TRD. This trial will compare the efficacy of MST to right unilateral ultra-brief pulse width electroconvulsive therapy (RUL-UB-ECT) with a combined primary endpoint of remission of depression and superior cognitive adverse effects in 260 patients with TRD. Amelioration of suicidal ideation will be assessed as a secondary endpoint. Inpatients or outpatients, over 18 years of age with a MINI International Neuropsychiatric Interview (MINI) diagnosis of non-psychotic major depressive disorder (MDD) can be enrolled in the study provided that they meet illness severity and full eligibility criteria. Participants are randomized to receive MST or RUL-UB ECT, 2-3 days per week over seven weeks, or a maximum of 21 treatments. The study will involve before-, during-, and after-treatment assessments of depression severity, suicidal ideation, subjective side-effects, and cognitive performance consistent with an intent-to-treat study design approach.

DISCUSSION

Positive results from this trial could have an immediate and tremendous impact for patients with TRD. If MST demonstrates comparable antidepressant treatment efficacy to ECT, but with greater cognitive safety, it could rapidly be adopted into clinical practice. Indeed, given that the administration of MST is nearly identical to ECT, the majority of ECT facilities in North America could readily adopt MST. Furthermore, the potential for cognitive safety could lead to improved treatment acceptability. Healthcare providers, patients and care partners, and policymakers would therefore demand this form of convulsive therapy.

TRIAL STATUS

Enrollment for this study began on June 26, 2018, and is estimated to complete recruitment by July 2024. At the time of submission, we have enrolled and randomized 117 participants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03191058 , Registered on June 19, 2017. Primary sponsor: Daniel Blumberger (DMB), Principal Investigator Daniel.Blumberger@camh.ca , 416-535-8501 x 33662 Contact for public queries: DMB, Daniel.Blumberger@camh.ca Contact for scientific queries: ZJD, Zdaskalakis@health.ucsd.edu.

Does electroconvulsive therapy cause brain damage: An update

Electroconvulsive therapy (ECT) is an effective modality of treatment for a variety of psychiatric disorders. However, it has always been accused of being a coercive, unethical, and dangerous modality of treatment. The dangerousness of ECT has been mainly attributed to its claimed ability to cause brain damage. This narrative review aims to provide an update of the evidence with regard to whether the practice of ECT is associated with damage to the brain. An accepted definition of brain damage remains elusive. There are also ethical and technical problems in designing studies that look at this question specifically. Thus, even though there are newer technological tools and innovations, any review attempting to answer this question would have to take recourse to indirect methods. These include structural, functional, and metabolic neuroimaging; body fluid biochemical marker studies; and follow-up studies of cognitive impairment and incidence of dementia in people who have received ECT among others. The review of literature and present evidence suggests that ECT has a demonstrable impact on the structure and function of the brain. However, there is a lack of evidence at present to suggest that ECT causes brain damage.

Subjective memory complaints after electroconvulsive therapy: systematic review

Aims and methodFew studies have looked at subjective memory impairment from electroconvulsive therapy (ECT) after treatment completion. We aimed to systematically review all available evidence for subjective post-treatment effects. RESULTS: We included 16 studies in this review. There was considerable between-study heterogeneity in clinical population, ECT modality and assessment scales used. The most common assessment scale (eight studies) was the Squire Subjective Memory Questionnaire. The majority of studies reported an improvement in subjective memory after ECT, which correlated with improved depression scores. Subjective complaints were fewer in studies that used ultra-brief pulse ECT. Longer pulse widths were associated with more subjective complaints, as was female gender and younger age of treatment in the largest study.Clinical implicationsThere is considerable heterogeneity between studies, limiting meaningful conclusions. Ultra-brief pulse ECT appears to result in fewer subjective complaints.Declaration of interestNone.

Leveraging Neuroplasticity to Enhance Adaptive Learning: The Potential for Synergistic Somatic-Behavioral Treatment Combinations to Improve Clinical Outcomes in Depression

Until recently, therapeutic development in psychiatry was targeted solely toward symptom reduction. While this is a worthwhile goal, it has yielded little progress in improved therapeutics in the last several decades in the field of mood disorders. Recent advancements in our understanding of pathophysiology suggests that an impairment of neuroplasticity may be a critical part of the development of neuropsychiatric disorders. Interventions that enhance or modulate neuroplasticity often reduce depressive symptoms when applied as stand-alone treatments. Unfortunately, when treatments are discontinued, the disease state often returns as patients relapse. However, treatments that enhance or modulate plasticity not only reduce symptom burden, but also may provide an opportune window wherein cognitive or behavioral interventions could be introduced to harness a state of enhanced neuroplasticity and lead to improved longer-term clinical outcomes. Here, we review the potential of synergistically combining plasticity-enhancing and behavioral therapies to develop novel translational treatment approaches for depression. After reviewing relevant neuroplasticity deficits in depression, we survey biological treatments that appear to reverse such deficits in humans, including N-methyl-D-aspartate receptor modulators (ketamine, D-cycloserine), electroconvulsive therapy, and transcranial brain stimulation. We then review evidence that either directly or indirectly supports the hypothesis that a robust enhancement of neuroplasticity through these methods might promote the uptake of cognitive and behavioral interventions to enhance longer-term treatment outcomes through a synergistic effect. We identify key missing pieces of evidence and discuss future directions to enhance this emerging line of research.

Treatment of neurocognitive symptoms in unipolar depression: A systematic review and future perspectives

BACKGROUND

Cognitive symptoms in Major Depressive Disorder (MDD) are persistent and commonly entail neurocognitive impairment and a decline in quality of life. This systematic review gathers the current scientific evidence on therapeutic strategies for neuropsychological impairment in MDD.

METHOD

A systematic search on PubMed, PsycINFO and Clinicaltrials.gov was carried out on December 2016 according to PRISMA using Boolean terms to identify interventions for the treatment of cognitive dysfunction in MDD. Only English-written articles providing original data and focusing in adults with MDD were included with no time restrictions.

RESULTS

A total of 95 studies reporting data on 40 pharmacological and non-pharmacological interventions were included. Interventions were grouped into the following categories: 1) Pharmacological Therapies (antidepressants, stimulants, compounds acting on NMDA receptors, compounds acting on the cholinergic system, compounds showing anti-inflammatory or antioxidant properties, other mechanisms of action), 2) Physical Therapies and 3) Psychological Therapies, 4) Exercise. There are some promising compounds showing a positive impact on cognitive symptoms including vortioxetine, lisdexamfetamine or erythropoietin.

LIMITATIONS

The studies included showed significant methodological differences in heterogeneous samples. The lack of a standardized neuropsychological battery makes comparisons between studies difficult.

CONCLUSION

Current evidence is not sufficient to widely recommend the use of procognitive treatments in MDD although promising results are coming to light.

A Brief Measure for Assessing Patient Perceptions of Cognitive Side Effects After Electroconvulsive Therapy: The Subjective Assessment of Memory Impairment

OBJECTIVES

Directly inquiring about patient experiences of memory problems after ECT may alert clinicians to the existence of treatment side effects and provide an impression of their intrusiveness. In this study, we examined use of a novel and brief patient-reported measure to assess perceptions of memory side effects and their functional consequences before and after an acute ECT treatment course. These outcomes were compared with objective cognitive and subjective quality of life measures.

METHODS

Data for 75 patients who were prescribed an acute course of ECT were analyzed. Subjective and objective measures were assessed before ECT (pretreatment) and at posttreatment. Patient perceptions were assessed using the Subjective Assessment of Memory Impairment, which consists of two items: The Memory Problems item, and The Impact of Cognitive Adverse Events item. Objective cognitive outcomes were assessed using the Montreal Cognitive Assessment. Quality of life was assessed using the Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form.

RESULTS

Patient perceptions of their memory problems did not change across the ECT course, and their functional impact were considered less intrusive after ECT. Greater functional impact of memory impairment was related to poorer quality of life at posttreatment, but not at pretreatment. Subjectively rated cognitive functioning was not associated with objective cognitive outcomes.

CONCLUSIONS

The Subjective Assessment of Memory Impairment is a brief tool for measuring patient-rated memory function. Overall, patients did not report any change in subjective memory problems after ECT. Although perceptions of functional memory impairment and quality of life were related after ECT, there was no association with objectively assessed cognitive outcomes.

Early effects of modern electroconvulsive therapy on subjective memory in patients with mania or depression

CONTEXT

Although electroconvulsive therapy (ECT) is considered a very effective tool for the treatment of psychiatric diseases, memory disturbances are among the most important adverse effects.

AIMS

This study aimed to assess prospectively early subjective memory complaints in depressive and manic patients due to bilateral, brief-pulse ECT, at different stages of the treatment, compare the associations between psychiatric diagnosis, sociodemographic characteristics, and ECT characteristics.

SETTINGS AND DESIGN

This prospective study was done with patients undergoing ECT between November 2008 and April 2009 at a tertiary care psychiatry hospital of 2000 beds.

MATERIALS AND METHODS

A total of 140 patients, scheduled for ECT with a diagnosis of bipolar disorder (depressive or manic episode) or unipolar depression according to Diagnostic and Statistical Manual of Mental Disorders IV diagnostic criteria, were included in the study and invited to complete the Squire Subjective Memory Questionnaire (SSMQ) before ECT, after the first and third sessions and end of ECT treatment.

STATISTICAL ANALYSIS

Mean values were compared with the Kruskal-Wallis test and comparison of the longitudinal data was performed with a nonparametric longitudinal data analysis method, F1_LD_F1 design.

RESULTS

SSMQ scores of the patients before ECT were zero. SSMQ scores showed a decrease after the first and third ECT sessions and before discharge, showing a memory disturbance after ECT and were significantly less severe in patients with mania in comparison to those with depression.

CONCLUSIONS

These findings suggest an increasing degree of subjective memory complaints with bilateral brief-pulse ECT parallel to the increasing number of ECT sessions.

Detecting objective and subjective cognitive effects of electroconvulsive therapy: intensity, duration and test utility in a large clinical sample

BACKGROUND

Electroconvulsive therapy (ECT) is an effective treatment for depression but the extent and persistence of cognitive side-effects remain uncertain. It has been reported that there is little evidence that impairments last longer than up to 15 days post-ECT. However, relatively few studies have followed patients for even as long as 1 month post-ECT. Here we report results from a brief cognitive battery given prior to ECT and repeated five times up to 6 months post-ECT.

METHOD

In a retrospective case-note study of routinely collected clinical data 126 patients treated with ECT completed two neuropsychological tests [Cambridge Neuropsychological Test Automated Battery (CANTAB) spatial recognition memory (SRM) and Mini Mental State Examination (MMSE)] and two subjective reports of memory function, prior to ECT. Patients were reassessed following ECT and at 1, 3 and 6 months post-ECT although not all patients completed all assessments.

RESULTS

Performance relative to pre-ECT baseline was significantly poorer at each post-ECT assessment up to 3 months post-ECT using the CANTAB SRM, but was improved at 6 months. Conversely, MMSE score showed improvements relative to baseline from 1 month post-ECT. Mood and subjective memory scores improved following ECT and were correlated with one another, but not with either neuropsychological measure.

CONCLUSIONS

The CANTAB SRM task revealed reversible cognitive deficiencies relative to a pre-ECT baseline for at least 3 months following ECT, while MMSE score and patients' subjective reports showed only improvement. Visuospatial memory scores eventually exceeded baseline 6 months post-ECT.

Magnetic seizure therapy in an adolescent with refractory bipolar depression: a case report

Magnetic seizure therapy (MST) has shown efficacy in adult patients with treatment-resistant depression with limited impairment in memory. To date, the use of MST in adolescent depression has not been reported. Here we describe the first successful use of MST in the treatment of an adolescent patient with refractory bipolar depression. This patient received MST in an ongoing open-label study for treatment-resistant major depression. Treatments employed a twin-coil MST apparatus, with the center of each coil placed over the frontal cortex (ie, each coil centered over F3 and F4). MST was applied at 100 Hz and 100% machine output at progressively increasing train durations. Depressive symptoms were assessed using the 24-item Hamilton Depression Rating Scale and cognitive function was assessed with a comprehensive neuropsychological battery. This adolescent patient achieved full remission of clinical symptoms after an acute course of 18 MST treatments and had no apparent cognitive decline, other than some autobiographical memory impairment that may or may not be related to the MST treatment. This case report suggests that MST may be a safe and well tolerated intervention for adolescents with treatment-resistant bipolar depression. Pilot studies to further evaluate the effectiveness and safety of MST in adolescents warrant consideration.

Neurocognitive effects after brief pulse and ultrabrief pulse unilateral electroconvulsive therapy for major depression: a review

BACKGROUND

Neurocognitive functioning is well known to be affected after ECT. However quantified data about the severity of the cognitive impairment after ultrabrief pulse and brief pulse ECT are limited, which makes it hard to judge its clinical relevance.

METHODS

To review all prospective studies using right unilateral (ultra) brief pulse index electroconvulsive therapy published up until February 2011 which used at least one instrument for cognitive assessment before and after ECT. The severity and persistence of neurocognitive side effects immediately (one to seven days post ECT), between one and six months and after six months post ECT were assessed by calculating effect sizes using Cohen's d.

RESULTS

Ten studies fulfilled the inclusion criteria and provided detailed information to compute effect sizes. The results indicate loss of autobiographical memory and impairment of verbal fluency, anterograde verbal and non-verbal memory immediately after brief pulse RUL ECT. To a lesser extent impairment of working memory and reduced speed of processing is found. Autobiographical memory is the only domain still being impaired between one and six months post ECT, but improved in this period. Verbal fluency normalized to baseline performance between one and six months post ECT whereas anterograde verbal and non-verbal memory normalized or even improved. Speed of processing improved within six months after ECT. Long-term data on these cognitive domains were not available. Based on two of the ten included studies the results suggest that ultrabrief pulse RUL ECT causes less decline in autobiographical and anterograde memory after ECT than brief pulse RUL ECT.

LIMITATIONS

This review may be limited because of the small number of included studies and due to unreliable effect sizes. Furthermore, few data were available for non-memory domains and cognitive functioning after six months.

CONCLUSIONS

Loss of autobiographical memory is still present between one and six months after unilateral brief pulse ECT. Ultrabrief pulse RUL ECT shows less decline in autobiographical memory. Other neurocognitive impairments after brief pulse RUL ECT seem to be transient.

Stimulus pulse-frequency-dependent efficacy and cognitive adverse effects of ultrabrief-pulse electroconvulsive therapy in patients with major depression

BACKGROUND

: Electroconvulsive therapy (ECT) is a highly effective treatment for major depression. New ECT devices with shorter pulse widths seem to induce seizures more effectively at a lower seizure threshold and with fewer cognitive adverse effects. Suprathreshold right unilateral (RUL) ultrabrief-pulse ECT with pulse widths between 0.25 and 0.30 millisecond seem to be especially effective with regard to efficacy and cognitive adverse effects. A lower pulse frequency (50 pulses per second) in RUL ECT was found to be more efficient than a higher pulse frequency (200 pulses per second) in inducing seizures. However, effective stimulus dose can often be achieved only with high stimulus frequency, whereas the impact of increased stimulus frequency on antidepressant efficacy and cognitive adverse effects is not known.

METHODS

: Forty patients with major depression according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition were randomly assigned to 2 groups of 20 patients each and stimulated with either 40 or 100 Hz with equal initial stimulus doses in 9 sessions of suprathreshold RUL ultrabrief-pulse ECT. Depressive symptoms and measures of verbal and working memory were assessed for both groups.

RESULTS

: Patients in the 40-Hz condition showed significantly more improvement in Hamilton Rating Scale for Depression scores compared with patients in the 100-Hz condition after 9 ECT sessions. Frequency group had no significant impact on measures of verbal and working memory.

CONCLUSIONS

: Within the discussed limitations, our preliminary data suggest an advantage for administering stimulus dose in suprathreshold RUL ultrabrief-pulse ECT with a lower stimulus frequency (40 Hz) as compared with a higher frequency (100 Hz). Further studies are needed to assess whether increasing pulse widths or frequency is the better option for augmenting stimulus dose once other stimulus parameters are at a maximum.

Contrasting patterns of deficits in visuospatial memory and executive function in patients with major depression with and without ECT referral

BACKGROUND

The pretreatment neuropsychological profile of drug-resistant patients with major depressive disorder (MDD) referred for electroconvulsive therapy (ECT) may differ from that of their drug-respondent MDD counterparts. Such differences could help in identifying distinct MDD subtypes, thus offering insights into the neuropathology underlying differential treatment responses.

METHOD

Depressed patients with ECT referral (ECTs), depressed patients with no ECT referral (NECTs) and non-psychiatric Controls (matched groups, n=15) were assessed with memory and executive function tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

ECTs scored significantly lower than NECTs in the Mini-Mental State Examination (MMSE; p=0.01). NECTs performed worse than Controls in the Paired Associates Learning (PAL) task (p<0.03; Control/NECT p<0.01) and the Spatial Recognition Memory (SRM) task (p<0.05; Controls/NECTs p<0.05); ECTs performed between Controls and NECTs, not differing from either. In the Intra/Extradimensional (IED) set-shifting task, ECTs performed worse that Controls and NECTS (IED: p<0.01; Controls/ECTs p<0.01), particularly in the shift phases, which suggests reduced attentional flexibility. In Stockings of Cambridge (SOC), ECTs abandoned the test early more often than Controls and NECTs (H=11, p<0.01) but ECTs who completed SOC performed comparably to the other two groups.

CONCLUSIONS

A double dissociation emerged from the comparison of cognitive profiles of ECT and NECT patients. ECTs showed executive deficits, particularly in attentional flexibility, but mild deficits in tests of visuospatial memory. NECTs presented the opposite pattern. This suggests predominantly frontostriatal involvement in ECT versus temporal involvement in NECT depressives.

Self-evaluation of the cognitive effects of electroconvulsive therapy

OBJECTIVES

Using standard self-evaluation questionnaires, numerous studies have found that subjective memory improves shortly after electroconvulsive therapy (ECT). This change covaries strongly with depression severity and is not associated with objective amnestic effects or treatment parameters. We examined subjective evaluations of ECT's cognitive effects using a novel interview that directly inquired about global impact, in contrast to the standard method of inquiring about specific aspects of cognition.

METHODS

We conducted a prospective, randomized, double-masked trial comparing the effects of pulse width (0.3 vs 1.5 milliseconds) and electrode placement (right unilateral vs bilateral) on cognitive outcomes. Subjective evaluations were obtained before and during the week after the randomized ECT course, using the Cognitive Failures Questionnaire, the Squire Memory Complaint Questionnaire, and the novel Global Self-Evaluation of Memory. An extensive neuropsychological battery was administered at these time points.

RESULTS

Cognitive Failures Questionnaire and Squire Memory Complaint Questionnaire scores improved at post-ECT relative to pre-ECT, strongly covaried with depression severity (24-item Hamilton Depression Rating Scale scores) but not with objective amnestic deficits or treatment parameters. In contrast, the treatment conditions differed in post-ECT Global Self-Evaluation of Memory scores, and these scores were associated with objective amnestic effects.

CONCLUSIONS

In contrast to standard methods, direct questioning about global impact resulted in more negative views about ECT's cognitive effects, concordance with objective cognitive measures, and differences among treatment conditions. Patients may be more accurate in their assessment of ECT's adverse effects than had previously been suggested.

Electroconvulsive therapy-induced persistent retrograde amnesia: could it be minimised by ketamine or other pharmacological approaches?

BACKGROUND

Certain pharmacological agents administered during electroconvulsive therapy may have the potential to prevent persistent retrograde amnesia induced during electroconvulsive therapy. This review examines mechanisms for electroconvulsive therapy-induced retrograde amnesia, and evaluates the suitability of the anaesthetic ketamine for preventing this amnestic outcome.

METHODS

A review of human studies, animal models and theoretical models in light of memory dysfunction following electroconvulsive therapy was conducted. MEDLINE was searched from 1950 to April 2009 using the MeSH terms "electroconvulsive therapy", "memory", "memory short term", "memory disorders", "excitatory amino acid antagonists", and "ketamine". PREMEDLINE was searched using the terms "electroconvulsive therapy", "amnesia" and "ketamine". Additional keyword and reference list searches were performed. No language, date constraints or article type constraints were used.

RESULTS

Disruption of long term potentiation as a mechanism for electroconvulsive therapy-induced retrograde amnesia is well supported. Based on this putative mechanism, an N-methyl-D-aspartate receptor antagonist would appear suitable for preventing the retrograde amnesia. Available evidence in animals and humans supports the prediction that ketamine, an anaesthetic agent and N-methyl-D-aspartate receptor antagonist, could effectively prevent electroconvulsive therapy-induced persistent retrograde amnesia. Whilst there are concerns about the use of ketamine with electroconvulsive therapy, such as possible psychotomimetic effects, on balance this anaesthetic agent may improve or hasten clinical response to electroconvulsive therapy.

CONCLUSIONS

A clinical trial is warranted to determine if ketamine anaesthesia during electroconvulsive therapy can lessen persistent retrograde amnesia and improve therapeutic response. Electroconvulsive therapy with ketamine anaesthesia may provide effective antidepressant action with minimal side effects.

New-onset dissociative disorder after electroconvulsive therapy

Electroconvulsive therapy (ECT) is an exceptionally effective treatment for a number of psychiatric conditions; however, a common adverse effect is temporary cognitive impairment, especially memory loss. The dissociative disorders also involve disturbances of memory, as well as consciousness and personal identity, but are rarely iatrogenic. We report a case in which dissociative symptoms developed after ECT. A 51-year-old woman with hypothyroidism, migraine headaches, bipolar disorder, and anorexia by history was admitted for worsening depression with suicidal ideation. After a course of 7 right-sided ECT treatments, she experienced remarkable personality change, claiming that it was 1976 and behaving as though she was 30 years younger. Neuropsychological tests were normal, and her memory and former personality spontaneously returned 2 weeks later. This case illustrates that such events may be seen in patients with certain psychiatric profiles, and further studies are needed to determine the risk factors for the occurrence of dissociative episodes after ECT.

Using the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess the cognitive impact of electroconvulsive therapy on visual and visuospatial memory

BACKGROUND

The cognitive impact of electroconvulsive therapy (ECT) is rarely measured systematically in everyday clinical practice even though patient and clinician acceptance is limited by its adverse affect on memory. If patients are tested it is often with simple paper and pencil tests of visual or verbal memory. There are no reported studies of computerized neuropsychological testing to assess the cognitive impact of ECT on visuospatial memory.

METHOD

Twenty-four patients with severe depression were treated with a course of bilateral ECT and assessed with a battery of visual memory tests within the Cambridge Neuropsychological Test Automated Battery (CANTAB). These included spatial and pattern recognition memory, pattern-location associative learning and a delayed matching to sample test. Testing was carried out before ECT, during ECT, within the week after ECT and 1 month after ECT.

RESULTS

Patients showed significant impairments in visual and visuospatial memory both during and within the week after ECT. Most impairments resolved 1 month following ECT; however, significant impairment in spatial recognition memory remained. This is one of only a few studies that have detected anterograde memory deficits more than 2 weeks after treatment.

CONCLUSIONS

Patients receiving ECT displayed a range of visual and visuospatial deficits over the course of their treatment. These deficits were most prominent for tasks dependent on the use of the right medial temporal lobe; frontal lobe function may also be implicated. The CANTAB appears to be a useful instrument for measuring the adverse cognitive effects of ECT on aspects of visual and visuospatial memory.

Meta-analysis of initial seizure thresholds in electroconvulsive therapy

In electroconvulsive therapy (ECT), electrical dosage is determined using 'fixed-dose', 'age-based' dose, or empirical titration methods. Estimation of initial seizure threshold (IST) has been claimed to be imperative for suprathreshold dosing. This systematic review aimed to determine common levels of IST, to define cut-off values for high IST, and to summarize reported IST associated factors. Medline and PsycINFO were searched from 1966 to January 2008 and relevant references were cross-checked. Subject headings including ECT, seizure threshold, dosage, and dosing were used. All articles reporting on levels of IST and/or associated factors were included. Of 395 potentially relevant reports, 46 studies on 70 samples concerning 3,023 patients were selected. Nine samples (n = 306 patients) without available standard deviation and four samples (n = 275 patients) treated with mixed electrode placement were excluded. Meta-analysis was done on 30 unilaterally treated samples (n = 1,326 patients) and 27 bilaterally treated samples (n = 1,116 patients). In unilateral ECT, weighted mean of IST was 68.2 milliCoulombs (mC; 95% CI 63.2-73.3 mC), and in bilateral ECT 111.6 mC (95% CI 103.7-119.4 mC). Calculated cut-off values for high IST were 121 mC for unilateral ECT and 221 mC for bilateral ECT. According to the literature, male gender and use of bilateral electrode placement appeared to increase IST most prominently. In conclusion, calculated electrical doses for 'suprathreshold' right unilateral ECT and for 'moderate above threshold' bilateral ECT, using commonly reported IST levels, were in the same though narrower ranges as provided in 'fixed-dose' and 'half-age' based strategies, respectively.

The effects of ECT on cognitive functioning in the elderly: a review

BACKGROUND

Electroconvulsive therapy (ECT) as a single course or in maintenance form (M-ECT) is an effective treatment in depressed elderly. However, ECT may have adverse effects on cognition.

OBJECTIVE

To review all studies from 1980-2006 on ECT and cognition in the elderly with a minimum age of 55 years or a mean age of 55 years, and with valid measurements of cognition before and after ECT.

RESULTS

Nine out of the 15 eligible studies were focused exclusively on the elderly. Three studies reported verbal learning- and recall problems post ECT, while three studies found positive effects of ECT on memory, speed of processing and concentration. Global cognitive functioning in patients with cognitive impairment improved in all studies. At follow up, most studies reported improvement of cognitive functions. Learning verbal information and executive functioning were impaired in M-ECT patients whereas global cognition remained stable after M-ECT over a year.

CONCLUSIONS

To date research of ECT on cognitive functioning in the elderly is very limited. Small sample size, lack of controls, use of a single screening instrument and a short follow up period may explain the conflicting results. Given the clinical importance, more extensive research on cognition in elderly treated with ECT is urgently needed.

Differential effects of high-dose magnetic seizure therapy and electroconvulsive shock on cognitive function

BACKGROUND

Magnetic seizure therapy (MST) is under investigation as an alternative form of convulsive therapy that induces more focal seizures and spares cortical regions involved in memory. With a newly expanded version of the Columbia University Primate Cognitive Profile, we compared the cognitive effects of high-dose MST delivered at 100 Hz (6 x seizure threshold) with electroconvulsive shock (ECS) delivered at 2.5 x seizure threshold.

METHODS

Daily high-dose MST, ECS, and sham (anesthesia-only) were administered for 4 weeks each in a within-subject crossover design. Rhesus macaques (n = 3) were trained on five cognitive tasks assessing automatic memory, anterograde learning and memory, combined anterograde and retrograde simultaneous chaining, and spatial and serial working memory. Acutely after each intervention, monkeys were tested on the cognitive battery twice daily, separated by a 3-hour retention interval.

RESULTS

Subjects were slower to complete criterion tasks (p values < .0001) after ECS, compared with sham and high-dose MST. Moreover, time to task-completion after high-dose MST did not differ from sham. Of six measures of accuracy, treatment effects were found in four; in all of these, ECS but not MST fared worse than sham. On all accuracy and time to completion measurements, subjects performed as well after high-dose MST as subjects from a previous study on moderate-dose MST.

CONCLUSIONS

These findings provide evidence that high-dose MST results in benign acute cognitive side-effect profile relative to ECS and are in line with our previous studies.

The effect of electroconvulsive therapy on autobiographical memory: a systematic review

OBJECTIVES

In the last 20 years, an increasing number of articles have been published about effects of electroconvulsive therapy (ECT) on memory. Here, we review autobiographical memory studies in particular because there have been conflicting reports about the extent and persistence of ECT effects and the period before treatment from which memories are most likely to be affected.

METHODS

Five psychological and medical databases (MEDLINE, PubMed, PsychINFO, ScienceDirect, and Web of Knowledge) were searched from 1980 to 2007, yielding 15 studies of ECT and autobiographical memory.

RESULTS

Evidence suggests that autobiographical memory impairment does occur as a result of ECT. Objective measures found memory loss to be relatively short term (<6 months posttreatment), whereas subjective accounts reported amnesia to be more persistent (>6 months post-ECT). Electroconvulsive therapy predominantly affects memory of prior personal events that are near the treatment (within 6 months). Autobiographical memory loss is reduced by using brief pulse ECT rather than sine wave-unilateral positioning of electrodes rather than bilateral-and by titrating electrical current relative to the patient's own seizure threshold.

CONCLUSIONS

Further research is required to determine memory loss associated with ECT, controlling for the direct effects of the depressive state.

The cognitive side effects of modern ECT: patient experience or objective measurement?

This article explores the subjective experience of cognitive deficits of patients who are treated with electroconvulsive therapy, by using actual comments made in clinical situations. The material is divided into 4 themes: the need for clear information, the importance of validation of experience, the impact of daily disruptions, and the issue of self-esteem. It is argued that despite the low correlation which exists between objectively measured cognitive function and the subjectively experienced impairment, the discrepancy creates a need to take both perspectives into consideration rather than to rely on one or the other. The validity and limitations of using personal narrative as a relevant clinical parameter are discussed.

A review of the cognitive effects of electroconvulsive therapy in older adults

OBJECTIVE

To review studies that examined the impact of electroconvulsive therapy (ECT) on cognitive functioning in depressed older people.

METHODS

Studies were systematically retrieved using PsychINFO and MEDLINE, with additional articles sourced from lists of references. Given our aged-care focus, study participants had a minimum mean age of 60 years, with no single participant younger than 50 years.

RESULTS

Twenty-seven studies met our criteria. Apart from evidence of interictal slowing of information processing speed, there were mixed results with regard to the impact of ECT on other cognitive domains. Factors contributing to this variability in results include the lack of discrimination between unilateral, bilateral, or mixed electrode placement; the inclusion of patients with dementia; the small sample sizes; and the use of tests insensitive to subtle cognitive changes.

CONCLUSIONS

The effect of ECT in elderly recipients' cognition remains unclear, and further research with more critically selected methods is required. In the meantime, we recommend that clinicians regularly administer brief focused cognitive tests before, during, and after treatment to monitor progress.

Monitoring of cognitive effects during a course of electroconvulsive therapy: recommendations for clinical practice

Cognitive impairment is the most important side effect of electroconvulsive therapy (ECT), and if detected early, modifications to treatment can be made to reduce the severity of it. Various guidelines suggest that regular, detailed monitoring of cognitive function should be routine during ECT. We hypothesize that such monitoring would be able to detect cognitive effects of ECT at an early stage but that this would require careful selection of tests to be both sensitive and practical in routine clinical practice. We review evidence regarding the sensitivity of various cognitive tests to the effects of ECT. From this, we suggest a battery and testing schedule which may be both practical and useful in early detection of the cognitive effects of ECT.

Cognitive side effects of brief pulse electroconvulsive therapy: a review

Cognitive impairment remains a common side effect of brief pulse electroconvulsive therapy (ECT), and its minimization has been the motivation for many different treatment modifications over the decades. The level of impairment has been shown to vary according to different technical parameters of ECT including, but not limited to, electrode placement, dosage, and waveform, as well as patient factors, such as age and premorbid intellect. Most past research has focused the assessment on memory impairments associated with ECT. Specifically, ECT can result in both anterograde and retrograde memory impairments. However, the study of non-memory cognitive functions after ECT has been relatively neglected. Furthermore, although considerable recovery has been observed within weeks of treatment completion, data are lacking in the longer term. The following article presents an overview of what is currently known about the pattern and recovery of cognitive side effects of ECT. Controversies within the literature and areas requiring further research are highlighted.

A comparison of propofol and thiopentone use in electroconvulsive therapy: cognitive and efficacy effects

OBJECTIVE

The purpose of this study was to compare thiopentone and propofol administration for electroconvulsive therapy (ECT) in terms of associated efficacy and cognitive side effects in the immediate and medium term.

METHOD

Participants comprised 30 depressed patients who were administered either propofol or thiopentone as an anesthetic agent for ECT. Clinical rating scales and a battery of neuropsychological tests were administered at baseline, after 6 treatments, 1 to 3 days after treatment end point, and at 1-month follow-up.

RESULTS

Thiopentone administration was associated with advantages in efficacy and cognitive side effects compared with propofol administration.

CONCLUSIONS

This study reports some serendipitous findings regarding the comparative effects of the anesthetic agents, propofol and thiopentone. Although limited by small sample size, results suggest that thiopentone has advantages for use as an anesthetic agent with ECT compared with propofol. It also highlights the need for further investigation of the impact of anesthetic agents on the cognitive side effects and efficacy of ECT.

A naturalistic comparison of two right unilateral electroconvulsive therapy dosing protocols: 2-3X seizure threshold versus fixed high-dose

The aim of this study was to compare the outcomes associated with two differing right unilateral (RUL) electroconvulsive therapy (ECT) dosing protocols: 2-3X seizure threshold (2-3X ST) and fixed high dose (FHD) at 353 mC. A retrospective chart review was performed to compare patient outcomes during the implementation of two different dosing protocols: 2-3X ST from October 2000 to May 2001 and FHD from June 2001 to February 2002. A total of 56 patients received ECT under the 2-3X ST protocol, and 46 received ECT under the FHD protocol. In total, 13.6% of patients receiving ECT according to the 2-3X ST protocol received more than 12 ECT, whereas none of the FHD group received more than 12 ECT. The mean number of ECT per treatment course reduced significantly from 7.6 to 5.7 following the switch from the 2-3X ST protocol to the FHD protocol. There were no significant differences between the two groups in the incidence of adverse cognitive effects. ECT practitioners adhered to the 2-3X ST protocol for only 51.8% of ECT courses, with protocol adherence improving to 87% following introduction of the FHD protocol. Although this naturalistic retrospective chart survey had significant methodological limitations, it found that practitioners are more likely to correctly adhere to a fixed dose protocol, therefore, increasing its 'real world' effectiveness in comparison to titrated suprathreshold dosing techniques. The FHD protocol was associated with shorter courses of ECT than the 2-3X ST protocol, with no significant difference between the two protocols in clinically discernable adverse cognitive effects.

Recent advances in optimizing electroconvulsive therapy

This review aims to summarize and critically evaluate the evidence for recent advances and alternative approaches in electroconvulsive therapy (ECT) technique. Novel developments in ECT research are also mentioned. An EMBASE literature search was undertaken of clinical trials, case reports and research updates on novel and alternative approaches in ECT practice and research, including alternative electrode placements, variations in stimulus configuration, and novel developments (magnetic seizure therapy, focal electrical stimulation). The evidence for these approaches is reviewed, and implications for the optimizing of ECT in clinical practice are discussed. Evidence from studies suggests that unilateral ECT be given at substantially suprathreshold doses (at least 6 times seizure threshold) for maximizing efficacy, while bilateral ECT is likely to be effective at doses of 1.5-2.5 times seizure threshold. There is some evidence to support the use of bifrontal ECT, although further research is required to establish its efficacy and side-effects relative to standard unilateral and bilateral electrode placements. Other alternative electrode placements have been minimally studied. More advantageous efficacy side-effect outcomes may be achieved by reducing the pulse width and/or frequency of the ECT stimulus. Lastly, novel developments using alternative means of seizure induction (magnetic fields, focal electrical stimulation) may hold promise for the future. Clinical practice should be guided by a careful appraisal of the available evidence for alternative approaches in ECT technique.

[Electroconvulsive therapy at the Department of Psychiatry and Psychotherapy, University of Munich. Development during the years 1995-2002]

BACKGROUND

So far, electroconvulsive therapy (ECT) has been proven to be a reliable and the most effective somatic treatment of depression or schizophrenia. This holds especially true for disturbances, which are refractory to pharmacological treatments.

PATIENTS AND METHODS

We evaluated 4803 treatments in 445 patients. Main outcome criteria were efficacy and tolerability of treatment. Moreover, prospectively recorded neurophysiological parameters that might influence treatment outcome and treatment modalities and were assessed in a retrospective study design.

RESULTS

During the last 7 years developmental changes show an increasing call for ECT treatment. Despite not being able to satisfy all demands the number of treatments more than doubled during the time period investigated. According to the latest scientific knowledge, especially in unipolar ECT, higher stimulation energy has been used to provide better treatment efficacy. Nevertheless, this was accompanied by a lower incidence of cognitive side effects. Due to the better tolerability of the treatment and the prospective neurophysiological indices, it appears that treatment quality has improved in recent years. Overall treatment efficacy was not improved, but could be maintained on a stable high level. This is presumably due to a stronger negative selection of patients with more pharmacotherapy-refractory disturbances.

CONCLUSION

ECT still represents an important option in the treatment of therapy-resistant depression and schizophrenia despite recent progress in neuropsychopharmacology.

Building an ECT service: an outcomes-equivalent approach

OBJECTIVE

Specific guidelines, ongoing controversies in technique and audit reviews have made clinicians wary about continuing in electroconvulsive therapy (ECT). This paper attempts to reassure practitioners by incorporating such changes into a simple approach to ECT based on outcomes equivalence.

METHOD

A selected compilation of the recent literature was used to describe a model for starting and/or continuing an effective ECT service.

RESULTS

It was suggested that a useful way of approaching ECT service delivery is to focus on what is actually important, getting patients better, and to do so within the context and capability of each hospital.

CONCLUSIONS

ECT is a changing field. Remaining true to the core principles of clinical practice, patient selection and technique, provides a basis for beginning, continuing and further developing an effective ECT service.

Right unilateral electroconvulsive therapy at six times seizure threshold

OBJECTIVE

To examine the clinical practice of right unilateral electroconvulsive therapy (ECT) administered at six times seizure threshold (6 x RUL ECT).

METHOD

A retrospective review of all patients who received 6 x RUL ECT between July 2000 and June 2002.

RESULTS

Twenty-one patients across a range of ages and diagnostic groups received D'Elia unilateral ECT at a seizure dosage at or above 388.8 milliCoumbs (mC). In order to sustain predetermined criteria for seizure adequacy, energy was increased in 71% of patients. Final seizure lengths of 45 s electroencephalographic (EEG) activity, 28 s motor activity (cuffed) and a post-ictal suppression index (PSI) of 83% were recorded. Eighty percent of patients responded after a mean of 7.0 treatments. Cognitive side-effects were noted in 21% of patients. Fifty-two percent relapsed on average 6.3 months after the last treatment despite continuation pharmacotherapy.

CONCLUSIONS

6 x RUL ECT was found to be clinically effective, associated with cognitive side-effects and relapse. The debate over electrode placement is likely to continue.

Safety and feasibility of magnetic seizure therapy (MST) in major depression: randomized within-subject comparison with electroconvulsive therapy

Magnetic seizure therapy (MST) is a novel means of performing convulsive therapy using rapidly alternating strong magnetic fields. MST offers greater control of intracerebral current intensity than is possible with electroconvulsive therapy (ECT). These features may result in a superior cognitive side effect profile for MST, while possibly retaining the efficacy of ECT. The objective of this study was to determine whether MST and ECT differ in seizure characteristics, and acute objective and subjective cognitive side effects. A total of 10 inpatients in a major depressive episode referred for ECT were enrolled in this randomized, within-subject, double-masked trial. Seizure threshold was determined with MST and ECT in the first two sessions of a course of convulsive therapy, with order randomized. The remaining two sessions consisted of suprathreshold stimulation with MST and ECT. A neuropsychological battery and side effect rating scale were administered by a masked rater before and after each session. Tonic-clonic seizures were elicited with MST in all patients. Compared to ECT, MST seizures had shorter duration, lower ictal EEG amplitude, and less postictal suppression. Patients had fewer subjective side effects and recovered orientation more quickly with MST than ECT. MST was also superior to ECT on measures of attention, retrograde amnesia, and category fluency. Magnetic seizure induction in patients with depression is feasible, and appears to have a superior acute side effect profile than ECT. Future research will be needed to establish whether MST has antidepressant efficacy.

New developments in electroconvulsive therapy and magnetic seizure therapy

New findings regarding the mechanisms of action of electro-convulsive therapy (ECT) have led to novel developments in treatment technique to further improve this highly effective treatment for major depression. These new approaches include novel placements, optimization of electrical stimulus parameters, and new methods for inducing more targeted seizures(eg, magnetic seizure therapy [MST]). MST is the use of transcranial magnetic stimulation to induce a seizure. Magnetic fields pass through tissue unimpeded, providing more control over the site and extent of stimulation than can be achieved with ECT. This enhanced control represents a means of focusing the treatment on target cortical structures thought to be essential to antidepressant response and reducing spread to medial temporal regions implicated in the cognitive side effects of ECT. MST is at an early stage of development. Preliminary results suggest that MST may have some advantages over ECT in terms of subjective side effects and acute cognitive functioning. Studies designed to address the antidepressant efficacy of MST are underway. As with all attempts to improve convulsive therapy technique, the clinical value of MST will need to be established through controlled clinical trials. This article reviews the experience to date with MST, and places this work in the broader context of other means of optimizing convulsive therapy in the treatment of depression.

Improvement in response times for simple and complex tasks after electroconvulsive therapy

BACKGROUND

Electroconvulsive therapy (ECT) has gone through fundamental changes since its introduction in 1938 and has developed from a frightening and distrusted procedure into an effective and safe treatment for people with severe psychiatric disorders. This study suggests that ECT has an effect on the response times of simple and complex tasks.

METHODS

We had two groups. The first group consisted of eight patients suffering from severe therapy-resistant depression. They were treated with ECT. The second group consisted of eight sex- and age-matched persons who were treated conventionally with antidepressive medication. The authors measured auditory and visual response times of both simple and complex tasks in run A and run B on two different days. In the ECT group, the first measurement took place 1 day before a session of ECT, the second 3 h following a session of ECT. In the depressive control group, the two measurements were performed on two different days but at most within 4 days.

RESULTS

The response times of the depressive subjects treated with ECT are prolonged in both run A and run B compared to those of the depressive control group. The response times in run B are reduced compared to run A on the whole. However the reduction is stronger in the ECT group than the one taking place in the depressive control group between the two runs.

CONCLUSIONS

The considerable decrease of the response times from run A to run B in the ECT group compared to the depressive control group gives further evidence that ECT has a positive effect on important information processing parameters.

Update on magnetic seizure therapy: a novel form of convulsive therapy

Magnetic seizure therapy (MST) refers to the use of transcranial magnetic stimulation to induce a seizure for therapeutic purposes. MST is under investigation as a means of improving the safety profile of electroconvulsive therapy (ECT). Although both MST and ECT induce seizures through electrical stimulation of the brain, the electric field induced by MST is more focal and limited than that induced by ECT. Because magnetic fields pass through tissue unimpeded, there is greater control over the site and extent of stimulation with MST than can be achieved with ECT. This enhanced control represents a means of focusing the treatment on target cortical structures thought to be essential to antidepressant response and of reducing spread to medial temporal regions implicated in the cognitive side effects of ECT. MST is currently at an early stage of development. This article reviews the experience with MST in animal models and initial human investigations. Preliminary results have demonstrated the feasibility of performing MST in the clinical setting, and there are suggestions that MST may have advantages over ECT in terms of subjective side effects and some measures of acute cognitive functioning. The antidepressant efficacy of MST is not yet known, but studies designed to address that critical issue are underway. As with all attempts to refine convulsive therapy techniques (such as modifications in stimulation parameter configurations and electrode placement), the ultimate clinical value of MST will need to be established through controlled clinical trials.

Stimulus titration and ECT dosing

The seizure threshold to electroconvulsive therapy (ECT) is defined entirely by the duration of the induced seizure, is multidetermined, and varies enormously with a wide variety of patient and treatment factors, including especially the parameters of the ECT stimulus. No consistent relationship has ever been detected between the clinical antidepressant response to ECT and either the threshold or the duration of the induced seizure. The stimulus titration method for determining the seizure threshold (titration-threshold dosing) was the central research tool used to reverse years of dogma by proving that the induced seizure of ECT is not alone sufficient to explain the therapeutic properties of ECT, and that the interaction between dosage and treatment electrode placement is critical in this regard. In clinical use, however, titration-threshold dosing has proven less than fully effective in optimizing the stimulus dose for ECT-better results are consistently obtained with age-based or fixed high-dose methods. The lack of a direct correlation between either seizure threshold or duration and clinical ECT response is an irremediable flaw of the titration-threshold method as clinically applied. New approaches are now called for in which ECT stimulus dosage is set and adjusted ("titrated") according to the clinical antidepressant response of the patient or to measurable correlates thereof: maximum sustained electroencephalogram (EEG) ictal power, EEG postictal suppression, induced interictal EEG delta activity, peak heart rate, maximum sustained EEG coherence, and postictal EEG coherence reduction, all of which have been found by various investigators to be related to the clinical antidepressant response to ECT.