Pharmacological attenuation of electroconvulsive therapy--induced cognitive deficits: theoretical background and clinical findings

Crucial role of autophagy in propofol-treated neurological diseases: a comprehensive review

Neurological disorders are the leading cause of disability and death globally. Currently, there is a significant concern about the therapeutic strategies that can offer reliable and cost-effective treatment for neurological diseases. Propofol is a widely used general intravenous anesthetic in the clinic. Emerging studies demonstrate that propofol exerts neuroprotective effects on neurological diseases and disorders, while its underlying pathogenic mechanism is not well understood. Autophagy, an important process of cell turnover in eukaryotes, has been suggested to involve in the neuroprotective properties developed by propofol. In this narrative review, we summarized the current evidence on the roles of autophagy in propofol-associated neurological diseases. This study highlighted the effect of propofol on the nervous system and the crucial roles of autophagy. According to the 21 included studies, we found that propofol was a double-edged sword for neurological disorders. Several eligible studies reported that propofol caused neuronal cell damage by regulating autophagy, leading to cognitive dysfunction and other neurological diseases, especially high concentration and dose of propofol. However, some of them have shown that in the model of existing nervous system diseases (e.g., cerebral ischemia-reperfusion injury, electroconvulsive therapy injury, cobalt chloride-induced injury, TNF-α-induced injury, and sleep deprivation-induced injury), propofol might play a neuroprotective role by regulating autophagy, thus improving the degree of nerve damage. Autophagy plays a pivotal role in the neurological system by regulating oxidative stress, inflammatory response, calcium release, and other mechanisms, which may be associated with the interaction of a variety of related proteins and signal cascades. With extensive in-depth research in the future, the autophagic mechanism mediated by propofol will be fully understood, which may facilitate the feasibility of propofol in the prevention and treatment of neurological disorders.

Electroconvulsive therapy for treating patients with agitation and related behavioral disorders due to dementia: a systematic review

Behavioral disturbances are clinically relevant in patients with dementia, and pharmacological regimens to mitigate these symptoms have provided limited results. Proven to be effective in several psychiatric conditions, electroconvulsive therapy is a potentially beneficial strategy for treating severe agitation due to dementia.

Objective

This review aimed to examine the publications on the efficacy, safety and tolerability of electroconvulsive therapy in treating patients with agitation due to dementia.

Methods

We performed a systematic analysis on the electroconvulsive therapy to treat patients with dementia and coexisting severe agitation. Articles were classified according to the level of evidence based on methodological design. Patients received an acute course of electroconvulsive therapy, often followed by maintenance intervention.

Results

We selected 19 studies (156 patients; 64.1% women; 51-98 years old), which met the inclusion criteria: one case-control study by chart analysis (level of evidence 2); one open-label study (level of evidence 3); three historical/retrospective chart analyses (level of evidence 4); and 14 case series/reports (level of evidence 5). No randomized, sham-controlled clinical trials (level of evidence 1) were identified, which represents the main methodological weakness. Some patients had postictal delirium, cardiovascular decompensation and cognitive changes, lasting for a short time.

Conclusions

Overall, patients achieved significant improvement in agitation. However, the main finding of the present review was the absence of methodological design based on randomized and sham-controlled clinical trials. Despite methodological limitations and side effects requiring attention, electroconvulsive therapy was considered a safe and effective treatment of patients with severe agitation and related behavioral disorders due to dementia.

Rivastigmine for ECT-induced cognitive adverse effects in late life depression (RECALL study): A multicenter, randomized, double blind, placebo-controlled, cross-over trial in patients with depression aged 55 years or older: Rationale, objectives and methods

BACKGROUND

Cognitive side-effects are an important reason for the limited use of electroconvulsive therapy (ECT). Cognitive side-effects are heterogeneous and occur frequently in older persons. To date, insight into these side-effects is hampered due to inconsistencies in study designs and small sample sizes. Among all cognitive side-effects, confusion and delirious states are especially troublesome for patients, relatives and clinicians. In particular inter-ictal delirium-like states are worrisome, since they may lead to premature treatment discontinuation. Besides a need for further insight into determinants of cognitive side-effects of ECT, there is a great need for treatment options.

METHODS AND DESIGN

The Rivastigmine for ECT-induced Cognitive Adverse effects in Late Life depression (RECALL) study combines a multicenter, prospective cohort study on older patients with depression, treated with ECT, with an embedded randomized, placebo-controlled cross-over trial to examine the effect of rivastigmine on inter-ictal delirium. Patients are recruited in four centers across the Netherlands and Belgium. We aim to include 150 patients into the cohort study, in order to be able to subsequently include 30 patients into the trial. Patients are included in the trial when inter-ictal delirium, assessed by the Confusion Assessment method (CAM), or a drop in Mini Mental State Examination (MMSE) score of ≥4 during ECT, develops. In the cohort study, comprehensive measurements of ECT-related cognitive side-effects-and their putative determinants-are done at baseline and during the ECT-course. The primary outcome of the clinical trial is the effectiveness of rivastigmine on inter-ictal delirium-severity, assessed with a change in the Delirium Rating Scale-Revised-98. Secondary outcomes of the clinical trial are several ECT-characteristics and side-effects of rivastigmine.

DISCUSSION

This study is the first clinical trial with a focus on ECT-induced, inter-ictal delirium. The cohort provides the basis for recruitment of patients for the cross-over trial and additionally provides an excellent opportunity to unravel cognitive side-effects of ECT and identify putative determinants. This paper describes the rationale and study protocol.

CLINICAL TRIAL REGISTRATION

EudraCT 2014-003385-24.

Efficacy of donepezil for the attenuation of memory deficits associated with electroconvulsive therapy

We sought to confirm and extend the findings of studies that reported that acetylcholinesterase inhibitor drugs protect against electroconvulsive therapy (ECT)-induced cognitive impairment. We randomized 30 patients with depression (n=24) or schizophrenia (n=6) to receive either donepezil (10 mg/day; n=15) or placebo (n=15) during a fixed course of 6 thrice-weekly, modified, bifrontotemporal sine wave ECT, and for 30 days subsequently. We assessed memory using the Postgraduate Institute Memory Scale (PGI-MS) at baseline, and again at days 2, 7, and 30 after the ECT course. At baseline, memory functioning was comparable in the 2 groups. At 2 days post-ECT, memory functioning was impaired on almost all 10 subtests and on the total scale. At 30 days post-ECT, memory functioning improved to (numerically) above baseline levels on almost all subtests and on the total scale, with the bulk of the improvement evident by day 7, itself. There was no significant difference between groups in the primary outcome, improvement in PGI-MS scores between Days 2 and 30 post-ECT. On almost all subtests, also, there was no significant difference between groups. In summary, we found that donepezil (10 mg/day) did not improve memory outcomes after ECT.

The Efficacy and Safety of Concomitant Psychotropic Medication and Electroconvulsive Therapy (ECT)

Electroconvulsive therapy (ECT) is an effective treatment for severe psychiatric disorders. Patients referred to ECT are often taking multiple medications, many of which can potentially affect the safety and efficacy of their course of ECT. This review evaluates the impact of a variety of psychotropic medications often used in conjunction with ECT and examines strategies to optimize their management. The review encompasses mood stabilizers, antidepressants, benzodiazepines, antiepileptics, antipsychotics, and other commonly used psychotropics.

Prophylactic cognitive enhancers for improvement of cognitive function in patients undergoing electroconvulsive therapy: A systematic review and meta-analysis

OBJECTIVE

Cognitive enhancers, including cholinesterase inhibitors and memantine, are used to treat dementia, but their effect for reducing post-electroconvulsive therapy (post-ECT) cognitive side effects is unclear. We conducted a systematic review and meta-analysis to assess the effectiveness of cognitive enhancers in the prevention of cognitive side effects due to ECT.

METHODS

We identified relevant studies by searching electronic databases (e.g., PubMed, EMBASE, Web of Science, Cochrane Library). Only studies published up to October 2019 comparing cognitive enhancer vs placebo for cognitive function after ECT were included. The primary outcome extracted from the studies was cognitive function score.

RESULTS

Five studies with 202 patients were included in this study. The cognitive enhancer group (CEG) had a significantly higher cognitive function score. Moreover, sensitivity analysis showed that no individual study had a significant impact on the overall results.

CONCLUSIONS

This meta-analysis revealed that cognitive enhancers might improve cognitive function and reduce ECT-induced cognitive side effects. Nevertheless, more high-quality randomized controlled trials (RCTs) with long-term follow-up are still needed to make the final conclusion.

Comparison of the efficacy and safety of melatonin and memantine in the alleviation of cognitive impairments induced by electroconvulsive therapy: A randomized clinical trial

The purpose of this study was to assess and compare the efficacy and safety of melatonin and memantine in the alleviation of cognitive disorders in patients diagnosed with major depressive disorder (MDD) undergoing electroconvulsive therapy (ECT). Patients undergoing ECT for treatment of MDD were randomly allocated to the melatonin (3 mg/d) or memantine (5 mg/d) groups. The participants received either melatonin or memantine (tablet) through the ECT therapy, which was started at beginning the first day of ECT and continued to the sixth session. The Modified Mental State Examination (MMSE) was used to evaluate cognitive function before and after the intervention. Frothy eligible patients (22 females and 18 males) were studied. There was no significant difference between two groups in terms of demographic characteristics, hemodynamic parameters and baseline MMSE and item 3 MMSE. The Memantine group scored significantly higher at the end of the ECT sessions either by MMSE or item 3MMSE than the baseline (P = 0.04 and P = 0.03, respectively). In the melatonin group, both MMSE and item 3MMSE scores were decreased significantly than the baseline (p = 0.03 and p = 0.02, respectively). No withdrawal was observed due to the drugs' adverse effects. It seems that memantine (5 mg/d) is more effective than melatonin (3 mg/d), to alleviate cognitive disorders induced by ECT.

Therapeutic and prophylactic role of cognitive enhancers in electroconvulsive therapy-induced cognitive deficits

OBJECTIVES

The objective is to evaluate the pattern of cognitive deficits after electroconvulsive therapy (ECT); to ascertain the role of various psychosocial, illness and treatment-related parameters on cognitive functions after ECT; and to evaluate the effect of donepezil on various cognitive deficits.

MATERIALS AND METHODS

A triple-blind randomized controlled trial was undertaken. Ninety patients undergoing ECT were included into study after due consent and institutional ethical approval. They were randomized into two groups: one using donepezil with ECT and the other using placebo with ECT. Various cognitive parameters were studied before ECT, after a course of ECT and after 4 weeks of last ECT. Findings were assessed in the light of available socialdemographic and clinical parameters and existing literature.

RESULTS

ECT was found to be an effective therapeutic modality. Immediate memory worsened over the course of ECT till after 4 weeks of ECT. Augmentation of donepezil was found useful. It sped up the improvement of general memory and working memory during ECT.

CONCLUSION

Donepezil has therapeutic and prophylactic benefit on cognition of patients undergoing ECT over the course of treatment till 4 weeks after the ECT.

Anesthetic effects on autophagy

Anesthetic agents provide patient comfort and optimize conditions for surgical and procedural interventions. These agents have been shown to modulate autophagy, which is a cellular mechanism that maintains tissue homeostasis by degrading and recycling excess, aged, or dysfunctional proteins. However, it is not always clear if upregulated autophagy is beneficial or harmful. This review assesses the anesthetic effects on autophagy. In the vast majority of studies, anesthetic modulation of autophagy is beneficial for cell survival.

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects.

Effect of Low Dose of Ketamine on Learning Memory Function in Patients Undergoing Electroconvulsive Therapy-A Randomized, Double-Blind, Controlled Clinical Study

OBJECTIVES

Converging evidence suggests that low doses of ketamine have antidepressant effects. The feasibility and safety of administering low doses of ketamine as adjunctive medication during electroconvulsive therapy (ECT) to enhance ECT efficacy and mitigate cognitive impairment has attracted much attention. This study investigated the effects of low doses of ketamine on learning and memory in patients undergoing ECT under propofol anesthesia.

METHODS

This randomized, placebo-controlled, double-blind study recruited patients with moderate to severe depressive disorders who failed to respond to antidepressants and were scheduled to receive ECT. Participants were randomly assigned to a study group, which received an intravenous administration of 0.3 mg/kg ketamine and then underwent ECT under propofol anesthesia, and a control group, which received isovolumetric placebo (normal saline) and then underwent ECT under propofol anesthesia. The Hamilton Depression Rating Scale was used to assess the severity of depression after ECT. Before and after the ECT course, the Mini-mental State Examination and the Wechsler Memory Scale-Chinese-Revision were used to assess global cognitive and learning and memory functions, respectively. Psychotropic effects were assessed using the Brief Psychiatric Rating Scale. Vital signs and other adverse events were recorded for each ECT procedure.

RESULTS

Of 132 patients recruited, 66 were assigned to each group; 63 patients in study groups and 64 patients in the control group completed the ECT course during the study. Afterward, the incidence of global cognitive impairment in the control group was higher than it was in the study group. In addition, the decline in the Wechsler Memory Scale-Chinese-Revision scale was greater in the control group than in the study group. The necessary ECT treatment times were shorter in the study group than in the control group (8 [7, 9] vs 9 [8, 10]). No significant escalations of the positive Brief Psychiatric Rating Scale scores or adverse events were observed in the study group when compared with the control group.

CONCLUSIONS

As adjunctive medication, ketamine can attenuate learning and memory impairment, especially for short-term memory, caused by ECT performed under propofol anesthesia. Ketamine can also reduce ECT treatment times during the therapy course without inducing significant adverse effects.

Acetylcholinesterase inhibitors for electroconvulsive therapy-induced cognitive side effects: a systematic review

OBJECTIVE

Electroconvulsive therapy (ECT) is an effective treatment for severe late-life depression; however, ECT-induced cognitive side effects frequently occur. The cholinergic system is thought to play an important role in the pathogenesis. We systematically reviewed the evidence for acetylcholinesterase inhibitors (Ache-I) to prevent or reduce ECT-induced cognitive side effects.

METHODS

A systematic search was performed in Pubmed, EMBASE, PsychINFO, and the Cochrane database to identify clinical trials investigating the effect of Ache-I on ECT-induced cognitive side effects. Key search terms included all synonyms for ECT and Ache-I. Risk of bias assessment was conducted by using the Cochrane Collaboration's tool.

RESULTS

Five clinical trials were eligible for inclusion. All studies focused on cognitive functioning as primary endpoint, but assessment of cognitive functioning varied widely in time point of assessment and in cognitive tests that were used. There was also great variety in study medication, route and time of administration and dosages, duration of drug administration, and ECT techniques. Finally, only two out of five studies were considered at low risk of bias. Despite the aforementioned shortcomings, without exception, all studies demonstrated significantly better cognitive performance in individuals treated with Ache-I.

CONCLUSIONS

Despite large heterogeneity in studies, Ache-I appear to have beneficial effects on ECT-induced cognitive side effects, supporting an association with the cholinergic system in ECT-induced cognitive impairment. Methodological sound studies controlling for putative confounders are warranted. Copyright © 2017 John Wiley & Sons, Ltd.

Key updates in the clinical application of electroconvulsive therapy

ECT is the oldest and most effective therapy available for the treatment of severe major depression. It is highly effective in individuals with treatment resistance and when a rapid response is required. However, ECT is associated with memory impairment that is the most concerning side-effect of the treatment, substantially contributing to the controversy and stigmatization surrounding this highly effective treatment. There is overwhelming evidence for the efficacy and safety of an acute course of ECT for the treatment of a severe major depressive episode, as reflected by the recent FDA advisory panel recommendation to reclassify ECT devices from Class III to the lower risk category Class II. However, its application for other indications remains controversial, despite strong evidence to the contrary. This article reviews the indication of ECT for major depression, as well as for other conditions, including catatonia, mania, and acute episodes of schizophrenia. This study also reviews the growing evidence supporting the use of maintenance ECT to prevent relapse after an acute successful course of treatment. Although ECT is administered uncommonly to patients under the age of 18, the evidence supporting its use is also reviewed in this patient population. Finally, memory loss associated with ECT and efforts at more effectively monitoring and reducing it are reviewed.

Propofol Mitigates Learning and Memory Impairment After Electroconvulsive Shock in Depressed Rats by Inhibiting Autophagy in the Hippocampus

Background

The present study explored the effects of propofol on hippocampal autophagy and synaptophysin in depression-model rats undergoing electroconvulsive shock (ECS).

Material/Methods

The rat depression model was established by exposing Sprague-Dawley rats to stress for 28 consecutive days. Forty rats were assigned randomly into the depression group (group D; no treatment), the ECS group (group E), the propofol group (group P), and the propofol + ECS group (group PE). Open field tests and sucrose preference tests were applied to evaluate the depression behavior; and Morris water maze tests were used to assess the learning and memory function of the rats. Western blotting was used to detect the expression of Beclin-1 and LC3-II/I; and ELISA was applied to assess the expression of synaptophysin.

Results

Rats in group E and group PE scored higher in the open field and sucrose preference tests compared with those in group D. Furthermore, rats in group E also had a longer escape latency, a shorter space exploration time, and increased expression of Beclin-1, LC3-II/I, and synaptophysin. Compared with group E, rats in group PE possessed a shorter escape latency, a longer space exploration time, reduced expression of Beclin-1, LC3-II/I, and synaptophysin.

Conclusions

Propofol could inhibit excessive ECS-induced autophagy and synaptophysin overexpression in the hippocampus, thus protecting the learning and memory functions in depressed rats after ECS. The inhibitory effects of propofol on the overexpression of synaptophysin may result from its inhibitory effects on the excessive induction of autophagy.

Cognitive Impairment and Electroconvulsive Therapy in Geriatric Depression, What Could be the Role of Rivastigmine? A Case Series

Electroconvulsive therapy (ECT), albeit highly effective in treating depression, is frequently associated with cognitive impairment, either temporary or more persistent. Especially in older patients, who generally respond even better, serious cognitive impairment during the course of ECT may lead to premature termination of ECT. Treatment of this cognitive impairment is of utmost importance. In this case series report, we present the effect of rivastigmine, an acetylcholinesterase inhibitor, on cognitive impairment in three older, severely depressed patients during or after a course of ECT. An improvement of cognitive functioning, in particular a decline of confusional symptoms, was observed in two patients with structural brain alterations associated with aging. In the other patient, who suffered primarily from amnesia, no effect of rivastigmine was observed. These preliminary results emphasize the need for detailed profiling of cognitive impairment when developing a research design to study the potential benefits of rivastigmine in the prevention or treatment of cognitive impairment in severely depressed patients treated with ECT.

Memantine in the prevention or alleviation of electroconvulsive therapy induces cognitive disorders: A placebo controlled trial

The purpose of this study was to evaluate the effect of memantine administration on the adverse cognitive effects of electroconvulsive therapy (ECT). Forty patients diagnosed with a major depressive disorder for which ECT was indicated as a treatment for their current episode were randomly allocated to either the memantine (5mg/day) group or the placebo group. All patients underwent the same protocol for anaesthesia and ECT procedures. The patients received memantine or the placebo for the whole period of ECT treatment, starting the day before ECT and continuing until the fourth session of ECT. The Modified Mental State Examination (MMSE) was used for the assessment of cognition before and after the trial. Regarding MMSE and item 3 MMSE (related to recent memory), the memantine group scored significantly higher at the end of ECT sessions than the control group (P=0.02, P<0.001, respectively). Our data support the hypothesis that memantine may reduce cognitive impairment following ECT. Memantine could be both a safe and well-tolerated treatment for use with ECT.

Further improving the cognitive effect profile of electroconvulsive therapy (ECT): the case for studying carbamylated erythropoietin

Electroconvulsive therapy (ECT) remains the most effective acute treatment for severe depression and several other psychiatric illnesses. However, its use has been limited by concerns about cognitive adverse effects. ECT may cause temporary cognitive impairment in some patients, typically anterograde amnesia for 1-2 weeks after a course of treatment, and circumscribed retrograde amnesia. These cognitive effects largely disappear within days to weeks after treatment. Efforts to find a pharmacological agent to reduce the cognitive effects of ECT have largely been unsuccessful, with the possible exception of thyroid hormone. We review the literature on pharmacological attempts to attenuate ECT's cognitive effects, and propose a novel neuroprotective and neurotrophic agent, carbamylated erythropoietin (CEPO), for this indication.

Propofol prevents electroconvulsive-shock-induced memory impairment through regulation of hippocampal synaptic plasticity in a rat model of depression

BACKGROUND

Although a rapid and efficient psychiatric treatment, electroconvulsive therapy (ECT) induces memory impairment. Modified ECT requires anesthesia for safety purposes. Although traditionally found to exert amnesic effects in general anesthesia, which is an inherent part of modified ECT, some anesthetics have been found to protect against ECT-induced cognitive impairment. However, the mechanisms remain unclear. We investigated the effects of propofol (2,6-diisopropylphenol) on memory in depressed rats undergoing electroconvulsive shock (ECS), the analog of ECT in animals, under anesthesia as well as its mechanisms.

METHODS

Chronic unpredictable mild stresses were adopted to reproduce depression in a rodent model. Rats underwent ECS (or sham ECS) with anesthesia with propofol or normal saline. Behavior was assessed in sucrose preference, open field and Morris water maze tests. Hippocampal long-term potentiation (LTP) was measured using electrophysiological techniques. PSD-95, CREB, and p-CREB protein expression was assayed with Western blotting.

RESULTS

Depression induced memory damage, and downregulated LTP, PSD-95, CREB, and p-CREB; these effects were exacerbated in depressed rats by ECS; propofol did not reverse the depression-induced changes, but when administered in modified ECS, propofol improved memory and reversed the downregulation of LTP and the proteins.

CONCLUSION

These findings suggest that propofol prevents ECS-induced memory impairment, and modified ECS under anesthesia with propofol improves memory in depressed rats, possibly by reversing the excessive changes in hippocampal synaptic plasticity. These observations provide a novel insight into potential targets for optimizing the clinical use of ECT for psychiatric disorders.

Speed of response in ultrabrief and brief pulse width right unilateral ECT

Ultrabrief pulse width stimulation electroconvulsive therapy (ECT) results in less cognitive side-effects than brief pulse ECT, but recent work suggests that more treatment sessions may be required to achieve similar efficacy. In this retrospective analysis of subjects pooled from three research studies, time to improvement was analysed in 150 depressed subjects who received right unilateral ECT with a brief pulse width (at five times seizure threshold) or ultrabrief pulse width (at six times seizure threshold). Multivariate Cox regression analyses compared the number of treatments required for 50% reduction in depression scores (i.e. speed of response) in these two samples. The analyses controlled for clinical, demographic and treatment variables that differed between the samples or that were found to be significant predictors of speed of response in univariate analyses. In the multivariate analysis, older age predicted faster speed of response. There was a non-significant trend for faster time to 50% improvement with brief pulse ECT (p = 0.067). Remission rates were higher after brief pulse ECT than ultrabrief pulse ECT (p = 0.007) but response rates were similar. This study, the largest of its kind reported to date, suggests that fewer treatments may be needed to attain response with brief than ultrabrief pulse ECT and that remission rates are higher with brief pulse ECT. Further research with a larger randomized and blinded study is recommended.

Neuropsychological and mood effects of ketamine in electroconvulsive therapy: a randomised controlled trial

BACKGROUND

Preliminary evidence suggests that the use of ketamine during electroconvulsive therapy (ECT) may be neuroprotective against cognitive impairment and have synergistic antidepressant effects. This study tested whether the addition of ketamine reduced cognitive impairment and enhanced efficacy over a course of ECT, in a randomised, placebo-controlled, double-blind study.

METHODS

Fifty-one depressed patients treated with ultrabrief pulse-width right unilateral ECT were randomised to receive either ketamine (0.5mg/kg) or placebo (saline) in addition to thiopentone during anaesthesia for ECT. Neuropsychological outcomes (measured before ECT, after six treatments, and after the final ECT treatment) and mood outcomes (measured before ECT, and weekly after every three ECT treatments) were measured by a rater blinded to treatment condition.

RESULTS

Neuropsychological outcomes did not differ between groups. The ECT-ketamine group had a slightly greater improvement in depressive symptoms over the first week of treatment and at one-week follow up, though there was no overall difference in efficacy at the end of the ECT course. No psychomimetic effects were detected.

LIMITATIONS

The study was conducted in a clinical setting, so not all aspects of ECT treatment were fully controlled. Thiopentone doses differed slightly between groups, in order to accommodate the addition of ketamine to the anaesthetic.

CONCLUSIONS

The addition of ketamine did not decrease cognitive impairment in patients having ultrabrief pulse-width right unilateral ECT, but was safe and slightly improved efficacy in the first week of treatment and at one-week follow up.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.gov ID: NCT00680433. Ketamine as an anaesthetic agent in electroconvulsive therapy (ECT). www.clinicaltrials.gov.

Administration of a selective glucocorticoid antagonist attenuates electroconvulsive shock-induced retrograde amnesia

Mifepristone, a glucocorticoid and progesterone receptor antagonist, has been shown to attenuate retrograde amnesia induced by repeated electroconvulsive shocks (ECS). We examined the efficacy of CORT 108297, a selective glucocorticoid antagonist, in this regard. Adult, male, Wistar rats (n = 69) received either vehicle or CORT 108297 (1 mg/kg) 2 h before each of 5 once-daily true or sham 30 mC ECS. Recall of previous exposure to a noxious stimulus in a passive avoidance (step-through) paradigm was tested 1 day after the 5-ECS course. Analyses were conducted using recall operationalized in different ways: using the absolute final latency scores; defining adequate recall as a final latency of 30 s or greater; defining perfect recall as a final latency of 180 s; and using visual, subjective assessments of animal behavior. ECS was associated with significant impairment of recall, and this impairment was significantly attenuated by CORT 108297 on all outcome measures (with the exception of the perfect recall analyses, where outcomes narrowly missed statistical significance). In conclusion, these findings strengthen previous data from our laboratory implicating glucocorticoid mechanisms in ECS-induced retrograde amnesia. We suggest that the administration of a selective glucocorticoid receptor antagonist shortly before electroconvulsive therapy (ECT) treatments may attenuate the deleterious effect of ECT-induced acute hypercortisolemia on neural mechanisms involved in learning and memory.

Propofol protects against impairment of learning-memory and imbalance of hippocampal Glu/GABA induced by electroconvulsive shock in depressed rats

PURPOSE

General anesthetics are believed to induce amnesia. However, propofol can ameliorate cognitive deficits induced by electroconvulsive therapy (ECT), a treatment for mental disorders. This study aimed at investigating the possible molecular mechanism as well as the effects of propofol on learning-memory impairment in depressed rats induced by ECS (electroconvulsive shock, the analog of ECT to animals).

METHODS

Rats were treated with ECS (or sham ECS) pretreated with intraperitoneal injection of propofol (100 mg/kg) (or normal saline, 0.01 l/kg) after being treated with chronic unpredictable mild stresses to reproduce an animal model of depression. Sucrose preference test, open field test, and Morris water maze were used to assess behavioral changes. Hippocampal glutamate (Glu) and γ-aminobutyric acid (GABA) levels were measured with liquid chromatography, and glutamic acid decarboxylase 65 (GAD65) was assayed immunohistochemically. Additionally, rats undergoing ECS that were pretreated with pentobarbital sodium (45 mg/kg) were included for behavioral tests and electroencephalogram recording for comparison with rats undergoing ECS that were pretreated with propofol or normal saline.

RESULTS

ECS rats pretreated with propofol or pentobarbital sodium exhibited similar decreased seizure durations as compared with ECS rats pretreated with normal saline. ECS pretreated with normal saline aggravated learning-memory deficits whereas ECS pretreated with propofol or pentobarbital sodium did not. Rats undergoing ECS pretreated with propofol showed better memory than those undergoing ECS after pretreatment with pentobarbital sodium. ECS pretreated with normal saline downregulated the ratio of Glu/GABA and upregulated GAD65 expression; all these molecular changes were nearly normalized to the level of control group by ECS pretreated with propofol. There were no significant differences of depressive behaviors between groups treated with ECS.

CONCLUSIONS

The data suggest that propofol alleviated ECS-induced learning-memory impairment without interfering with the antidepressant efficacy of ECS, possibly by inhibiting excessive expression of GAD65 and maintaining the balance between glutamatergic and GABAergic amino acids neurotransmitters in the hippocampus.

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.

Successful use of donepezil in treatment of cognitive impairment caused by maintenance electroconvulsive therapy: a case report

Cognitive deficits are commonly associated with maintenance electroconvulsive therapy (ECT). Treatment of these cognitive deficits is important but difficult. Cholinergic pathways are involved in these side effects, and donepezil, a cholinesterase inhibitor, may be useful for improvement of cognition. In this case report, we describe for the first time successful use of donepezil in treating cognitive deficits associated with maintenance ECT. The role of cholinesterase inhibitors in the treatment of cognitive deficits caused by ECT needs further studies.

A comparison of RUL ultrabrief pulse (0.3 ms) ECT and standard RUL ECT

An important goal in electroconvulsive therapy (ECT) research is to minimize associated cognitive side-effects while maintaining its high efficacy. This study explored the use of a novel approach, right unilateral (RUL) ECT with an ultrabrief pulsewidth (0.3 ms) (RUL-UB), in comparison with standard RUL ECT. Seventy-four depressed in-patients received RUL-UB ECT at six times seizure threshold, and 22 patients received standard RUL ECT (1.0 ms pulsewidth) at five times seizure threshold. Formal, prospective evaluations of mood and cognitive functioning over the treatment course were done by a rater blinded to treatment condition. Efficacy was maintained using the ultrabrief pulsewidth, with equivalent numbers of responders and remitters to the standard RUL ECT group, although the speed of response was slower. Cognitive outcomes were superior in the RUL-UB ECT group, particularly in the retention of verbal and visual information, as well as in retrograde autobiographical memory.

Celecoxib as an in vivo probe of cyclooxygenase-2 mechanisms underlying retrograde amnesia in an animal model of ECT

BACKGROUND

Cyclooxygenase-2 (COX-2) mechanisms are involved in glutamate-mediated learning and memory as well as in glutamatergic excitotoxicity. Electroconvulsive therapy (ECT)-induced amnesia may arise from glutamatergic excitotoxicity; if so, COX-2 inhibition may attenuate retrograde amnesia with ECT.

METHODS

Wistar rats which received celecoxib (15 mg/kg per day) or vehicle for 18 days were trained for 3 days on a passive avoidance task. On each of the next 3 days, rats which showed perfect learning (n=51) received true or sham suprathreshold electroconvulsive shocks (ECS; 60 mC) in a factorial design; daily dosing with drug or vehicle was continued. One day after the last ECS, recall of pre-ECS learning was tested.

RESULTS

ECS-treated rats showed impaired recall in the vehicle but not celecoxib group. Celecoxib significantly protected against ECS-induced retrograde amnesia; this benefit was independent of the drug-induced attenuation of ECS seizure duration.

CONCLUSIONS

Celecoxib may protect against ECS-induced retrograde amnesia by attenuating ECS-induced, COX-2-mediated glutamatergic excitotoxicity.