Electroconvulsive Therapy in Treatment-resistant Schizophrenia: Prediction of Response and the Nature of Symptomatic Improvement

The clinical features of patients with schizophrenia who respond to electroconvulsive therapy (ECT) are uncertain. There is also little information on the nature of symptomatic improvement with this treatment. Using a standardized protocol, 253 patients with treatment-resistant schizophrenia (TRS) were treated with combination ECT and flupenthixol, and 138 (54.5%) patients met response criteria. Independent of gender, duration of the current episode and severity of baseline negative symptoms were predictive of outcome. Duration of illness had weak relations with outcome and only among females. There were marked sex differences in other clinical features and symptoms associated with response. In contrast, no gender differences were observed in the nature of symptomatic improvement. Treatment resulted in marked improvement in specific positive symptoms, with an intermediate effect on affective symptoms, and no effect or worsening of specific negative symptoms. The findings challenge recommendations that long duration of illness or absence of affective symptoms portends poor response to ECT in patients with TRS. Gender may play a critical role in determining the features of the illness that predict outcome.

A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy

BACKGROUND

Optimal treatment remains uncertain for patients with cognitive impairment that persists or returns after standard IV antibiotic therapy for Lyme disease.

METHODS

Patients had well-documented Lyme disease, with at least 3 weeks of prior IV antibiotics, current positive IgG Western blot, and objective memory impairment. Healthy individuals served as controls for practice effects. Patients were randomly assigned to 10 weeks of double-masked treatment with IV ceftriaxone or IV placebo and then no antibiotic therapy. The primary outcome was neurocognitive performance at week 12-specifically, memory. Durability of benefit was evaluated at week 24. Group differences were estimated according to longitudinal mixed-effects models.

RESULTS

After screening 3368 patients and 305 volunteers, 37 patients and 20 healthy individuals enrolled. Enrolled patients had mild to moderate cognitive impairment and marked levels of fatigue, pain, and impaired physical functioning. Across six cognitive domains, a significant treatment-by-time interaction favored the antibiotic-treated group at week 12. The improvement was generalized (not specific to domain) and moderate in magnitude, but it was not sustained to week 24. On secondary outcome, patients with more severe fatigue, pain, and impaired physical functioning who received antibiotics were improved at week 12, and this was sustained to week 24 for pain and physical functioning. Adverse events from either the study medication or the PICC line were noted among 6 of 23 (26.1%) patients given IV ceftriaxone and among 1 of 14 (7.1%) patients given IV placebo; these resolved without permanent injury.

CONCLUSION

IV ceftriaxone therapy results in short-term cognitive improvement for patients with posttreatment Lyme encephalopathy, but relapse in cognition occurs after the antibiotic is discontinued. Treatment strategies that result in sustained cognitive improvement are needed.

Impairment of nonverbal recognition in Alzheimer disease: a PET O-15 study

OBJECTIVE

To characterize deficits in nonverbal recognition memory and functional brain changes associated with these deficits in Alzheimer disease (AD).

METHODS

Using O-15 PET, we studied 11 patients with AD and 17 cognitively intact elders during the combined encoding and retrieval periods of a nonverbal recognition task. Both task conditions involved recognition of line drawings of abstract shapes. In both conditions, subjects were first presented a list of shapes as study items, and then a list as test items, containing items from the study list and foils. In the titrated demand condition, the shape study list size (SLS) was adjusted prior to imaging so that each subject performed at approximately 75% recognition accuracy; difficulty during PET scanning in this condition was approximately matched across subjects. A control task was used in which SLS = 1 shape.

RESULTS

During performance of the titrated demand condition, SLS averaged 4.55 (+/-1.86) shapes for patients with AD and 7.53 (+/-4.81) for healthy elderly subjects (p = 0.031). However, both groups of subjects were closely matched on performance in the titrated demand condition during PET scanning with 72.17% (+/-7.98%) correct for patients with AD and 72.25% (+/-7.03%) for elders (p = 0.979). PET results demonstrated that patients with AD showed greater mean differences between the titrated demand condition and control in areas including the left fusiform and inferior frontal regions (Brodmann areas 19 and 45).

CONCLUSIONS

Relative fusiform and inferior frontal differences may reflect the Alzheimer disease (AD) patients' compensatory engagement of alternate brain regions. The strategy used by patients with AD is likely to be a general mechanism of compensation, rather than task-specific.

Strengthening clinical effectiveness trials: equipoise-stratified randomization

As psychiatric practice patterns evolve to take advantage of the growing list of treatments with proven efficacy, research studies with broader aims will become increasingly important. Randomized trials may need to accommodate multiple treatment options. In completely randomized designs, patients are assigned at random to one of the options, requiring that patients and clinicians find each of the options acceptable. In "clinician's choice" designs, patients are randomized to a small number of broad strategies and the choice of specific option within the broad strategy is left up to the clinician. The clinician's choice design permits some scope to patient and clinician preferences, but sacrifices the ability to make randomization-based comparisons of specific options. We describe a new approach, which we call the "equipoise stratified" design, that merges the advantages and avoids the disadvantages of the other two designs for clinical trials. The three designs are contrasted, using the National Institute of Mental Health Sequenced Treatment Alternatives to Relieve Depression trial as an example.

Vagus nerve stimulation (VNS) for treatment-resistant depression: efficacy, side effects, and predictors of outcome

This open pilot study of vagus nerve stimulation (VNS) in 60 patients with treatment-resistant major depressive episodes (MDEs) aimed to: 1) define the response rate; 2) determine the profile of side effects; and, most importantly; 3) establish predictors of clinical outcome. Participants were outpatients with nonatypical, nonpsychotic, major depressive or bipolar disorder who had not responded to at least two medication trials from different antidepressant classes in the current MDE. While on stable medication regimens, the patients completed a baseline period followed by device implantation. A 2-week, single blind, recovery period (no stimulation) was followed by 10 weeks of VNS. Of 59 completers (one patient improved during the recovery period), the response rate was 30.5% for the primary HRSD(28) measure, 34.0% for the Montgomery-Asberg Depression Rating Scale (MADRAS), and 37.3% for the Clinical Global Impression-Improvement Score (CGI-I of 1 or 2). The most common side effect was voice alteration or hoarseness, 55.0% (33/60), which was generally mild and related to output current intensity. History of treatment resistance was predictive of VNS outcome. Patients who had never received ECT (lifetime) were 3.9 times more likely to respond. Of the 13 patients who had not responded to more than seven adequate antidepressant trials in the current MDE, none responded, compared to 39.1% of the remaining 46 patients (p =.0057). Thus, VNS appears to be most effective in patients with low to moderate, but not extreme, antidepressant resistance. Evidence concerning VNS' long-term therapeutic benefits and tolerability will be critical in determining its role in treatment-resistant depression.

Focal prefrontal seizures induced by bilateral ECT

INTRODUCTION

It has been proposed that the greater efficacy of bilateral (BL) over right unilateral (RUL) electroconvulsive therapy (ECT) at low stimulus intensity is due to differences in site of seizure initiation. We hypothesized that focal prefrontal seizures are more common with BL than RUL administration.

METHOD

Records were reviewed of the 1,007 ECT treatments of 84 consecutive patients randomized to RUL or BL electrode placement.

RESULTS

Eight events were identified in which there was an electroencephalographic seizure without motor manifestation. All of these events occurred at titration sessions and with BL stimuli (p = 0.002). These events were more likely to occur later in the course of treatment.

DISCUSSION

We suggest that BL ECT may induce focal seizures in prefrontal areas and that these seizures are more likely to occur later in the treatment course.

ECT in the treatment of status epilepticus

INTRODUCTION

Owing to its potent anticonvulsant actions, electroconvulsive therapy (ECT) has been proposed as an intervention for treatment-resistant seizure disorders.

METHOD

We review the literature on the use of ECT in treatment-resistant epilepsy and status epilepticus (SE) and present a case of a patient who was in nonconvulsive SE for 26 days and then treated with ECT after all standard pharmacological strategies were exhausted. Because of skull defects, a novel electrode placement was used.

RESULTS

Owing to massively elevated seizure threshold attributable to concomitant anticonvulsant medications, extraordinarily high electrical dosage was needed for ECT to elicit generalized seizures. Status was terminated after three successful ECT-induced seizures. However, the long-term functional outcome of the patient was poor.

DISCUSSION

The role of ECT in the treatment algorithm for SE is discussed.

The definition and meaning of treatment-resistant depression

Most patients treated for an episode of unipolar or bipolar major depression are treatment resistant in the sense that the majority do not achieve full remission with the first somatic or psychosocial treatment they receive. Little attention has been given to formalizing criteria for evaluating the nature and extent of treatment resistance, even though determining the adequacy and outcome of prior treatment trials is key in clinical decision making about subsequent treatment. Furthermore, determining the adequacy of prior treatment is essential since substantial evidence indicates that large numbers of depressed patients are undertreated, resulting in prolonged episodes and the appearance of "pseudoresistance." Adequacy of antidepressant treatment trials should be defined in terms of thresholds for the dosage and duration of medication, adherence, and clinical outcome. The Antidepressant Treatment History Form is presented as one method to formalize the evaluation of treatment adequacy and treatment resistance.

Electro-convulsive therapy practices in the community

BACKGROUND

Controlled studies have demonstrated that variations in electro-convulsive therapy (ECT) technique impacts on efficacy and cognitive side effects. However, there is little information on the extent of variation in how ECT is practiced in community settings in the United States.

METHODS

A survey of practice patterns was conducted at ECT facilities in the greater New York City metropolitan area.

RESULTS

The 59 facilities varied considerably in many aspects of ECT practice, often clearly departing from the standards in the field. The more intensive the form of ECT used at facilities, the less likely was cognitive status assessed following the treatment course.

CONCLUSION

There is marked variability in the nature of ECT practices in community settings. The extent to which this variability impacts on the benefits and risks of ECT needs to be examined.

Vagus nerve stimulation in depression

Ever since the introduction of chemical and electrical convulsive treatment for psychiatric disorders in the 1930s and 1940s, biological techniques have been used extensively in the amelioration of a variety of psychiatric disorders. Techniques of recent vintage have included transcranial magnetic stimulation, deep brain stimulation and vagus nerve stimulation (VNS). Since VNS attenuates seizures in animal models, the treatment was initially developed and approved by the FDA for treatment of drug-resistant partial-onset epilepsy. Additional data, including the known neuroanatomy of the vagus nerve, effects of VNS on monoamines and mood improvement in patients with epilepsy who were treated with VNS, provided a rationale for further investigation in patients with primary mood disorders. VNS has been administered acutely for 10 weeks to 60 patients with treatment-resistant depression. Longer-term follow-up data has been analysed for the first 30 patients. Response rates have been at least 30% in the acute study. Similar to findings in epilepsy and in contrast to the usual results of long-term medication trials, longer term data regarding symptomatic and functional outcomes of depressed patients receiving VNS continue to look promising. As opposed to electroconvulsive therapy, VNS is not associated with cognitive impairment. These results have led to approval of VNS for the treatment of resistant depression (unipolar or bipolar) in both Europe and Canada. Currently, a pivotal double-blind acute study is underway in the US.

A unilateral, prolonged, nonconvulsive seizure in a patient treated with bilateral ECT

We report on a case of a 45-year-old man in an episode of major depression with psychotic features treated with bilateral electroconvulsive therapy (ECT). At the eighth treatment, he manifested unilateral, prolonged, nonconvulsive seizure activity on the left side, which lasted 351 seconds longer than seizure activity on the right, and was terminated with intravenous diazepam. This is the first report of a unilateral prolonged seizure. Its occurrence following bilateral ECT was particularly noteworthy. This case also highlights the importance of two-channel EEG recording during ECT. Without two recording channels we doubt that this event would have been detected, perhaps resulting in nonconvulsive status epilepticus.

Neuropsychological dysfunction in depressed suicide attempters

OBJECTIVE

Neuropsychological deficits in the context of psychiatric disease may be associated with suicide risk. In this study, neuropsychological performance was compared among depressed patients with at least one prior suicide attempt of high lethality, depressed patients with low-lethality prior attempts, depressed patients with no prior suicide attempts, and nonpatients.

METHOD

Fifty unmedicated patients in a major depressive episode (21 with no history of suicide attempts and 14 and 15 patients with previous attempts of low and high lethality, respectively) and 22 nonpatients were assessed. Groups were comparable in age, education, occupational level, and estimated premorbid intelligence. The neuropsychological battery produced scores within five composite domains: general intellectual functioning (current), motor functioning, attention, memory, and executive functioning.

RESULTS

Patients whose prior suicide attempts were of high lethality performed significantly worse than all groups on tests of executive functioning and were the only group to perform significantly worse than nonpatients on tests of general intellectual functioning, attention, and memory. A discriminant function analysis revealed two prominent dimensions in the data: one that discriminated high-lethality suicide attempters from all other groups (primarily associated with performance on tests of executive functioning) and another that discriminated all depressed patient groups from nonpatients (associated with performance on measures of attention and memory). For the patients with high-lethality prior suicide attempts, deficits did not appear to reflect diffuse brain damage from past attempts, since the results of tests commonly affected by diffuse injury were not selectively impaired.

CONCLUSIONS

Neuropsychological deficits in depressed patients with high-lethality prior suicide attempts suggest impairment of executive functioning beyond that typically found in major depression. This more extensive neuropsychological impairment in the context of depression may be a risk factor for severe suicide attempts.

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

OBJECTIVES

There is sparse evidence for differences in response to electroconvulsive therapy (ECT) between patients with bipolar or unipolar major depression, with virtually no information on speed of response. We contrasted a large sample of bipolar (BP) and unipolar (UP) depressed patients in likelihood and rapidity of clinical improvement with ECT.

METHODS

Over three double-blind treatment protocols, 228 patients met Research Diagnostic Criteria for UP (n = 162) or BP depression (n = 66). Other than lorazepam PRN (3 mg/day), patients were withdrawn from psychotropics prior to the ECT course and until after post-ECT assessments. Patients were randomized to ECT conditions that differed in electrode placement and stimulus intensity. Symptomatic change was evaluated at least twice weekly by a blinded evaluation team, which also determined treatment length.

RESULTS

Patients with BP and UP depression did not differ in rates of response or remission following the ECT course, or in response to unilateral or bilateral ECT. Degree of improvement in Hamilton Rating Scale for Depression scores following completion of ECT was also comparable. However, BP patients received significantly fewer ECT treatments than UP patients, and this effect was especially marked among bipolar ECT responders. Both BP I and BP II patients showed especially rapid response to ECT.

CONCLUSIONS

The BP/UP distinction had no predictive value in determining ECT outcome. In contrast, there was a large effect for BP patients to show more rapid clinical improvement and require fewer treatments than unipolar patients. The reasons for this difference are unknown, but could reflect a more rapid build up of anticonvulsant effects in BP patients.

Continuation pharmacotherapy in the prevention of relapse following electroconvulsive therapy: a randomized controlled trial

CONTEXT

Electroconvulsive therapy (ECT) is highly effective for treatment of major depression, but naturalistic studies show a high rate of relapse after discontinuation of ECT.

OBJECTIVE

To determine the efficacy of continuation pharmacotherapy with nortriptyline hydrochloride or combination nortriptyline and lithium carbonate in preventing post-ECT relapse.

DESIGN

Randomized, double-blind, placebo-controlled trial conducted from 1993 to 1998, stratified by medication resistance or presence of psychotic depression in the index episode.

SETTING

Two university-based hospitals and 1 private psychiatric hospital.

PATIENTS

Of 290 patients with unipolar major depression recruited through clinical referral who completed an open ECT treatment phase, 159 patients met remitter criteria; 84 remitting patients were eligible and agreed to participate in the continuation study.

INTERVENTIONS

Patients were randomly assigned to receive continuation treatment for 24 weeks with placebo (n = 29), nortriptyline (target steady-state level, 75-125 ng/mL) (n = 27), or combination nortriptyline and lithium (target steady-state level, 0.5-0.9 mEq/L) (n = 28).

MAIN OUTCOME MEASURE

Relapse of major depressive episode, compared among the 3 continuation groups.

RESULTS

Nortriptyline-lithium combination therapy had a marked advantage in time to relapse, superior to both placebo and nortriptyline alone. Over the 24-week trial, the relapse rate for placebo was 84% (95% confidence interval [CI], 70%-99%); for nortriptyline, 60% (95% CI, 41%-79%); and for nortriptyline-lithium, 39% (95% CI, 19%-59%). All but 1 instance of relapse with nortriptyline-lithium occurred within 5 weeks of ECT termination, while relapse continued throughout treatment with placebo or nortriptyline alone. Medication-resistant patients, female patients, and those with more severe depressive symptoms following ECT had more rapid relapse.

CONCLUSIONS

Our study indicates that without active treatment, virtually all remitted patients relapse within 6 months of stopping ECT. Monotherapy with nortriptyline has limited efficacy. The combination of nortriptyline and lithium is more effective, but the relapse rate is still high, particularly during the first month of continuation therapy.

Sham TMS: intracerebral measurement of the induced electrical field and the induction of motor-evoked potentials

Testing the therapeutic potential of transcranial magnetic stimulation (TMS) in controlled trials requires a valid sham condition. Sham TMS is typically administered by tilting the coil 45--90 degrees off the scalp, with one or two wings of the coil touching the scalp. Lack of cortical effects has not been verified. We compared sham manipulations in their thresholds for eliciting motor-evoked potentials (MEPs) in human volunteers and in intracerebral measurements of voltage induced in the prefrontal cortex of a rhesus monkey. Three types of sham (one-wing 45 degrees and 90 degrees and two-wing 90 degrees tilt) induced much lower voltage in the brain than active TMS (67--73% reductions). However, the two-wing 45 degrees sham induced values just 24% below active TMS. This sham was about half as potent in inducing MEPs over the motor cortex as active TMS. Some sham TMS conditions produce substantial cortical stimulation, making it critical to carefully select the sham manipulation for clinical trials.

Regional cerebral blood flow in mood disorders, V.: Effects of antidepressant medication in late-life depression

Twenty elderly outpatients with major depression were treated with either nortriptyline or sertraline. Resting regional cerebral blood flow (rCBF) was assessed by the planar (133)Xenon inhalation technique after a medication washout and following 6- 9 weeks of antidepressant treatment. At baseline, the depressed sample had reduced rCBF in frontal cortical regions when compared with 20 matched normal-control subjects. After treatment, Responders and Nonresponders differed in the expression of a specific topographic alteration, with Responders manifesting reduced perfusion in frontal regions. These findings are consistent with this group's previous report of reduced rCBF after response to electroconvulsive therapy (ECT) and suggest a common mechanism of action.

Decreased regional brain metabolism after ect

OBJECTIVE

The antidepressant action of ECT may be related to its anticonvulsant properties. Positron emission tomography (PET) studies of regional cerebral metabolic rate for glucose were used to test this hypothesis.

METHOD

Ten patients with major depression were studied with PET before and approximately 5 days after a course of bilateral ECT. Statistical parametric mapping was used to identify regions of decreased cerebral glucose metabolism.

RESULTS

Widespread regions of decreased regional cerebral glucose metabolism were identified after ECT, especially in the frontal and parietal cortex, anterior and posterior cingulate gyrus, and left temporal cortex. A region-of-interest analysis similarly indicated post-ECT reductions in regional cerebral glucose metabolism.

CONCLUSIONS

ECT reduces neuronal activity in selected cortical regions, a potential anticonvulsant and antidepressant effect.

Repetitive transcranial magnetic stimulation to SMA worsens complex movements in Parkinson's disease

OBJECTIVES

To evaluate the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS) for Parkinson's disease (PD) by delivering stimulation at higher intensity and frequency over longer time than in previous research. Promising beneficial effects on movement during or after rTMS have been reported.

METHODS

Ten patients with idiopathic PD were enrolled in a randomized crossover study comparing active versus sham rTMS to the supplementary motor area (SMA). Assessments included reaction and movement times (RT/MT), quantitative spiral analysis, timed motor performance tests, United Parkinson's Disease Rating Scale (UPDRS), patient self-report and guess as to stimulation condition.

RESULTS

Two of 10 patients could not tolerate the protocol. Thirty to 45 min following stimulation, active rTMS as compared with sham stimulation worsened spiral drawing (P=0.001) and prolonged RT in the most affected limb (P=0.030). No other significant differences were detected.

CONCLUSIONS

We sought clinically promising improvement in PD but found subclinical worsening of complex and preparatory movement following rTMS to SMA. These results raise safety concerns regarding the persistence of dysfunction induced by rTMS while supporting the value of rTMS as a research tool. Studies aimed at understanding basic mechanisms and timing of rTMS effects are needed.

The effects of vagus nerve stimulation on cognitive performance in patients with treatment-resistant depression

BACKGROUND

Chronic vagus nerve stimulation (VNS) is effective in the management of treatment-resistant epilepsy. Open-trial evidence suggests that VNS has clinically significant antidepressant effects in some individuals who experience treatment-resistant major depressive episodes. However, limited information regarding the effects of VNS on neurocognitive performance exists.

OBJECTIVE

The primary aim of this study was to determine whether VNS leads to neurocognitive deterioration.

METHOD

A neuropsychological battery was administered to 27 patients with treatment-resistant depression before and after 10 weeks of VNS. Thirteen neurocognitive tests sampled the domains of motor speed, psychomotor function, language, attention, memory, and executive function.

RESULTS

No evidence of deterioration in any neurocognitive measure was detected. Relative to baseline, improvement in motor speed (finger tapping), psychomotor function (digit-symbol test), language (verbal fluency), and executive functions (logical reasoning, working memory, response inhibition, or impulsiveness) was found. For some measures, improved neurocognitive performance correlated with the extent of reduction in depressive symptoms, but VNS output current was not related to changes in cognitive performance.

CONCLUSIONS

Vagus nerve stimulation in treatment-resistant depression may result in enhanced neurocognitive function, primarily among patients who show clinical improvement. Controlled investigation is needed to rule out the contribution of practice effects.

Vagus nerve stimulation. A potential therapy for resistant depression?

VNS builds on a long history of investigating the relationship of autonomic signals to limbic and cortical function and is one of the newest methods to physically alter brain function. VNS is a clinically useful anticonvulsant therapy in treatment resistant patients with epilepsy, and pilot data suggest that it has potential as an antidepressant therapy. The known anatomic projections of the vagus nerve suggest that VNS also might have other neuropsychiatric applications. Additional research is needed to clarify the mechanisms of action of VNS and the potential clinical utility of this intriguing new somatic portal into the CNS.

Different brain networks mediate task performance in normal aging and AD: defining compensation

OBJECTIVE

To determine whether the pathologic mechanisms of AD alter the brain networks subserving performance of a verbal recognition task.

BACKGROUND

Functional imaging studies comparing task-related activation in AD patients and controls generally have not used network analysis and have not controlled for task difficulty.

METHODS

H2 15O PET was used to measure regional cerebral blood flow in 14 patients and 11 healthy elders during the performance of a serial verbal recognition task under two conditions: low demand, with study list size (SLS) equal to one; and titrated demand, with SLS adjusted so that each subject recognized words at 75% accuracy. The Scaled Subprofile Model was used to identify networks of regionally covarying activity across these task conditions.

RESULTS

In the elders, higher SLS was associated with the recruitment of a network of brain areas involving left anterior cingulate and anterior insula (R2 = 0.94; p < 0.0001). Three patients also expressed this network. In the remaining patients, higher SLS was associated with the recruitment of an alternate network consisting of left posterior temporal cortex, calcarine cortex, posterior cingulate, and the vermis (R2 = 0.81, p < 0.001). Expression of this network was unrelated to SLS in the elders and more intact AD patients.

CONCLUSIONS

The patients' use of the alternate network may indicate compensation for processing deficits. The transition from the normal to the alternate network may indicate a point where brain disease has irreversibly altered brain function and thus may have important implications for therapeutic intervention.

Learning and memory in bipolar and unipolar major depression: effects of aging

OBJECTIVE

The goal of this study was to examine the effects of aging on neuropsychological functions in bipolar and unipolar major depression.

BACKGROUND

Earlier studies suggested that neurocognitive deficits in mood disorder patients correlate with duration and severity of illness and also that bipolar disorder has a more virulent course than unipolar disorder. We hypothesized that elderly patients with bipolar disorder will demonstrate greater neurocognitive dysfunction than young patients with bipolar disorder and elderly patients with unipolar disorder.

METHOD

A battery of tests of general intelligence and learning and memory was administered to 79 inpatients with major depression referred for electroconvulsive therapy. With patients 60 years of age and older defined as elderly, there were 29 young and 24 elderly unipolar patients and 13 young and 13 elderly bipolar patients.

RESULTS

Unipolar and bipolar patients did not differ in measures of general intelligence or global cognitive status. Generally, across tests of memory, young bipolar patients exhibited the best performance and elderly bipolar patients exhibited the poorest performance.

CONCLUSIONS

The results suggest that over the course of their illness, patients with bipolar disorder experience greater deterioration in memory functions than patients with unipolar disorder. Longitudinal studies are required to support the preliminary findings of this cross-sectional study.

Quantitative EEG during seizures induced by electroconvulsive therapy: relations to treatment modality and clinical features. I. Global analyses

This study examined the effects of electroconvulsive therapy (ECT) treatment conditions, patient individual difference factors, and clinical outcome on global electroencephalogram (EEG) power during and immediately following ECT-induced seizures. Sixty-two patients were randomized to ECT conditions differing in electrode placement (right unilateral versus bilateral) and stimulus dosage (just above seizure threshold versus 2.5 times seizure threshold). At the second and penultimate treatments, global total power (1.5-28.5 Hz) and global power in specific frequency bands were quantified in 19-lead EEG recordings of the generalized seizure and the immediate postictal period. Seizures induced with high dosage, and to lesser extent, with bilateral electrode placement, resulted in greater global power. Patient age, initial seizure threshold, and baseline depression severity were inversely related to global power during seizures. While superior clinical outcome following ECT was associated with greater global power during seizures, this effect was small. The factors associated with more robust seizure expression also resulted in greater postictal bioelectric suppression. Associations with treatment parameters and patient variables were stronger at the second than penultimate treatment. We conclude that manipulations of ECT technique strongly determine the magnitude of seizure expression, but relations with clinical outcome are weak. The findings raise doubt about the clinical utility of algorithms based on analysis of EEG features to guide ECT parameter selection.

Quantitative EEG during seizures induced by electroconvulsive therapy: relations to treatment modality and clinical features. II. Topographic analyses

This study tested three alternative theories of the mechanisms of therapeutic action of electroconvulsive therapy (ECT). The theories differed in predictions about the global and topographic effects of effective and ineffective forms of ECT on electroencephalogram (EEG) seizure expression. At the second treatment, 19-lead EEG recordings were obtained in 57 depressed patients randomized to conditions that differed in ECT electrode placement and stimulus dosage. Power in the delta frequency band was quantified during the seizure and analyzed with traditional multivariate methods and the Scaled Subprofile Model. Electrical dosage of the ECT stimulus had a powerful effect on ictal global delta power and, more so, than electrode placement. Greater ictal global delta power was associated with superior therapeutic outcome, but the magnitude of this effect was small. Effective forms of ECT resulted in a topography where delta power was accentuated in prefrontal EEG sites. High dosage right unilateral ECT also resulted in stronger asymmetry in prefrontal regions than the ineffective, low dosage right unilateral ECT. Greater bilateral generalization of seizure expression does not appear to be a prerequisite for therapeutic effects. Instead, more intense seizure expression in prefrontal regions may be critical for efficacy.

Effects of stimulus intensity on the efficacy of bilateral ECT in schizophrenia: a preliminary study

BACKGROUND

This preliminary study examined the effects of electrical stimulus intensity on the speed of response and efficacy of bilateral electroconvulsive therapy (ECT) in the treatment of schizophrenia.

METHODS

Sixty-two patients with schizophrenia received combination treatment with bilateral ECT and flupenthixol. Using a randomized, double-blind design, the effects of three dosages of the ECT electrical stimulus were examined. Patients were treated with a stimulus intensity that was just above seizure threshold, two-times threshold, or four-times threshold. Assessments of outcome used the Brief Psychiatric Rating Scale, Global Assessment of Functioning, and the Mini-Mental State Exam.

RESULTS

Thirty-three of sixty-two patients met remitter criteria, including maintaining improvement over a 3-week stabilization period. The dosage groups were equivalent in the number of patients who met remitter criteria. The low-dose remitter group (n = 11) received more ECT treatments and required more days to meet remitter status than both the twofold (n = 11) and fourfold remitter groups (n = 11). There was no difference among the groups in change in global cognitive status as assessed by the Mini-Mental State Exam.

CONCLUSIONS

This preliminary study indicates that treatment with high-dosage bilateral ECT speeds clinical response in patients with schizophrenia. There may be a therapeutic window of stimulus intensity in impacting on the efficacy of bilateral ECT, which needs further study. A more sensitive battery of cognitive tests should be used in future research.

Logical processing, affect, and delusional thought in schizophrenia

Deficits of logical reasoning have long been considered a hallmark of schizophrenia and delusional disorders. We provide a more precise characterization of "logic" and, by extension, of "deficits in logical reasoning." A model is offered to categorize different forms of logical deficits. This model acknowledges not only problems with making inferences, which is how logic deficits are usually conceived, but also problems in the acquisition and evaluation of premises (i.e., filtering of "input"). Early (1940-1969) and modern (1970-present) literature on logical reasoning and schizophrenia is evaluated within the context of the presented model. We argue that, despite a substantial history of interest in the topic, research to date has been inconclusive on the fundamental question of whether patients with delusional ideation show abnormalities in logical reasoning. This may be due to heterogeneous definitions of "logic," variability in the composition of patient samples, and floor effects among the healthy controls. In spite of these difficulties, the available evidence suggests that deficits in logical reasoning are more likely to occur due to faulty assessment of premises than to a defect in the structure of inferences. Such deficits seem to be provoked (in healthy individuals) or exacerbated (in patients with schizophrenia) by emotional content. The hypothesis is offered that delusional ideation is primarily affect-driven, and that a mechanism present in healthy individuals when they are emotionally challenged may be inappropriately activated in patients who are delusional.

The effects of electroconvulsive therapy on memory of autobiographical and public events

BACKGROUND

Retrograde amnesia is the most persistent cognitive adverse effect of electroconvulsive therapy (ECT); however, it is not known whether ECT has differential effects on autobiographical vs impersonal memories. This study examined the short- and long-term effects of differing forms of ECT on memory of personal and impersonal (public) events.

METHODS

Fifty-five patients with major depression were randomly assigned to right unilateral (RUL) or bilateral (BL) ECT, each at either low or high electrical dosage. The Personal and Impersonal Memory Test was administered by blinded raters at baseline, during the week after ECT, and at the 2-month follow-up. Normal controls were tested at matched intervals.

RESULTS

Shortly after ECT, patients recalled fewer events and event details than controls, with the deficits most marked for impersonal compared with personal events. Bilateral ECT caused more marked amnesia for events and details than RUL ECT, and especially for impersonal memories. These effects were independent of electrical dosage and clinical outcome. At the 2-month follow-up, patients had reduced retrograde amnesia, but continued to show deficits in recalling the occurrence of impersonal events and the details of recent impersonal events.

CONCLUSIONS

The amnestic effects of ECT are greatest and most persistent for knowledge about the world (impersonal memory,) compared with knowledge about the self (personal memory), for recent compared with distinctly remote events, and for less salient events. Bilateral ECT produces more profound amnestic effects than RUL ECT, particularly for memory of impersonal events.

Subjective memory complaints: a review of patient self-assessment of memory after electroconvulsive therapy

Interest in patients' subjective complaints about the adverse cognitive effects of electroconvulsive therapy (ECT) spans several decades. This article reviews the major areas that have been examined in relation to patients' subjective assessment of memory function: 1) technical aspects in the administration of ECT; 2) objective tests of cognitive function; and 3) clinical state. For the most part, subjective assessments of memory following ECT have relied on a single instrument, the Squire Subjective Memory Questionnaire (SSMQ). While older reports of the impact of the technical aspects of ECT on subjective memory assessment following ECT suggest a detectable negative influence with certain forms of treatment, most recent studies indicate that subjective memory improves following ECT. This shift in findings may be due to the change in practice from sine wave to brief-pulse ECT. While the impact of ECT on objective tests of memory is clear and reproducible, the relationship of objective findings to subjective memory assessment appears to be weak. Instead, subjective reports of cognitive function are strongly influenced by mood state. Current batteries of objective tests of memory may not include components that are most affected in reports about subjective memory. In addition, the literature mainly reports group effects, and sample sizes have been small. We lack data on the number of individuals who believe ECT has had a markedly negative effect on memory functioning, and on the characteristics of memory function in this subgroup of patients who complain of severe impairment. Furthermore, there is a paucity of information relating patient characteristics to subjective memory outcomes with ECT.

Electrophysiological correlates of the adverse cognitive effects of electroconvulsive therapy

Resting state, eyes closed, 19-lead EEG recordings were obtained at pre-ECT baseline and just prior to penultimate treatment and during the week following the ECT course in 59 patients with major depression. Patients had been randomized to ECT conditions that varied in electrode placement and stimulus intensity. The EEG data were submitted to power spectral analysis, and global and topographic effects were characterized for the delta and theta frequency bands. Relations between the EEG changes and scores on three cognitive measures were examined. The period of disorientation immediately following RUL ECT was associated with an accentuation of delta power in anterior frontal and temporal regions. Across the electrode placements, increased theta activity in left frontotemporal regions was associated with longer recovery of orientation. Post-ECT decrements in global cognitive status, as assessed by the modified Mini-Mental State exam, were associated with a greater increase in delta relative to theta power, globally across the cortex. The magnitude of retrograde amnesia for autobiographical events correlated with increased theta activity in left frontotemporal regions. The findings suggest that distinct neurophysiological changes subserve the therapeutic and adverse cognitive effects of ECT. Postictal disorientation and post-ECT retrograde amnesia appear to share a common physiological substrate.

Titrated moderately suprathreshold vs fixed high-dose right unilateral electroconvulsive therapy: acute antidepressant and cognitive effects

BACKGROUND

The antidepressant and cognitive side effects of right unilateral (RUL) electroconvulsive therapy (ECT) are reported to depend on the magnitude of the electrical stimulus relative to the seizure threshold. The stimulus doses explored in previous clinical trials of RUL ECT have generally been limited to 1 to 2.5 times the convulsive threshold and the antidepressant efficacy has been low compared with bilateral (BL) ECT. The present study compares the antidepressant and cognitive side effects of 2 RUL dosing strategies: titrated moderately suprathreshold and fixed high dose.

METHODS

Seventy-two adult patients with major depression were randomized to either titrated RUL ECT at 2.25 times initial seizure threshold (mean dose, 136 millicoulombes [mC]), or RUL ECT at a fixed dose of 403 mC. Primary outcome measures were antidepressant response and cognitive status 1 or 2 days after the course of ECT.

RESULTS

The 2 treatment groups were comparable in demographic and clinical characteristics prior to ECT. Both groups received a mean of 5.7 sessions of RUL ECT. Patients receiving fixed-dose ECT were more likely to have an antidepressant response at the end of the protocol (n = 49 [67%]) compared with those receiving titrated dosing (n = 28 [39%]). Furthermore, the likelihood of both antidepressant response and cognitive deficits increased as stimulus dose increased relative to initial seizure threshold, up through 8 to 12 times the threshold.

CONCLUSIONS

The antidepressant efficacy and cognitive side effects of RUL ECT are dependent on the magnitude of the stimulus dose relative to the seizure threshold, and a dose-response relationship extends through at least 12 times the seizure threshold.

A prospective, randomized, double-blind comparison of bilateral and right unilateral electroconvulsive therapy at different stimulus intensities

BACKGROUND

Controversy persists about the use of right unilateral (RUL) and bilateral (BL) electroconvulsive therapy (ECT). While RUL ECT results in less severe short-term and long-term cognitive effects, there is concern that it is less efficacious than BL ECT.

METHODS

In a double-blind study, 80 depressed patients were randomized to RULECT, with electrical dosages 50%, 150%, or 500% above the seizure threshold, or BL ECT, with an electrical dosage 150% above the threshold. Depression severity and cognitive functioning were assessed before, during, immediately after, and 2 months after ECT. Compared with baseline, responders had at least a 60% reduction in symptom scores 1 week after ECT, and were monitored for relapse for 1 year.

RESULTS

High-dosage RUL and BL ECT were equivalent in response rate (65%) and approximately twice as effective as low-dosage (35%) or moderate-dosage (30%) unilateral ECT. During the week after the randomized phase, BL ECT resulted in greater impairment than any dosage of unilateral ECT in several measures of anterograde and retrograde memory. Two months after ECT, retrograde amnestic deficits were greatest among patients treated with BL ECT. Thirty-three (53%) of the 62 patients who responded to ECT relapsed, without treatment group differences. The relapse rate was greater in patients who had not responded to adequate pharmacotherapy prior to ECT and who had more severe depressive symptoms after ECT.

CONCLUSION

Right unilateral ECT at high dosage is as effective as a robust form of BL ECT, but produces less severe and persistent cognitive effects.

Cerebral blood flow and metabolism in late-life depression and dementia

Late-life depression (LLD) is characterized by abnormalities in cerebral blood flow (CBF) and cerebral metabolic rate (CMR) for glucose. Unlike younger adults with major depression, global cortical CBF and CMR reductions have been reported in LLD. Patients with LLD are also characterized by topographic abnormalities, most commonly involving selective prefrontal, superior temporal, and anterior parietal cortex. The fate of these abnormalities with response to antidepressant treatment is highly uncertain, and heterogeneous findings have been reported in younger samples with major depression. The limited data in LLD suggest that response to electroconvulsive therapy or antidepressant medications does not involve reversal of baseline abnormalities but rather accentuation of prefrontal deficits. At minimum, these paradoxical findings suggest that abnormalities in CBF and CMR may be persistent in LLD and a trait characteristic. Characteristic profiles of CBF and CMR abnormalities have also been demonstrated in samples with Alzheimer's disease (AD) and other types of dementia. Functional imaging has shown sensitivity to disease severity and progression. Nonetheless, there is limited information regarding the sensitivity and specificity of the functional imaging modalities in the differential diagnosis of dementias. At present, the evidence does not support the use of functional imaging in isolation as a diagnostic tool. Rather, these imaging modalities may be considered as an adjunct to careful clinical assessment, either to improve diagnosis in early cases or to assist in subtyping difficult cases.

Determinants of seizure threshold in ECT: benzodiazepine use, anesthetic dosage, and other factors

The electrical dosage of the ECT stimulus impacts on efficacy and cognitive side effects, yet seizure threshold (ST) may vary as much as 50-fold across patients. It would be desirable to predict ST on the basis of patient and treatment characteristics. In particular, concerns have been raised that benzodiazepine use and higher dosage of barbiturate anesthetics elevate ST. In a three-site study, ST was quantified at the first ECT session using an identical empirical titration procedure in 294 patients who met RDC and DSM-IIIR criteria for a major depressive episode. ST varied over a 35-fold range across patients treated with right unilateral (RUL) (n = 267) and bilateral (BL) (n = 27) ECT. Higher ST was associated with BL electrode placement (p = 0.001). Among patients treated with RUL ECT, univariate analyses indicated that higher ST was associated with advanced age (p < 0.001), male gender (p < 0.001), greater burden of medical illness (p < 0.001), weight (p < 0.01), duration of mood disorder (p < 0.01), and history of previous ECT (p < 0.05). Average lorazepam dose in the 48 hours prior to ECT was not associated with ST, but was associated with decreased seizure duration (p < 0.01). Absolute, but not weight-adjusted, methohexital dose was associated with ST (p < 0.01). Multivariate analyses in patients treated with unilateral ECT showed that only 27.6% of the variance in ST (p < 0.0001) could be predicted. In the multivariate analyses, only age (p = 0.0001), gender (p = 0.01), and methohexital dose (p = 0.0001) were independently related to ST. Low dosage of lorazepam and methohexital dosage below 1 mg/kg are unlikely to impact on ST. Given the limited capacity to predict ST, empirical titration remains the only accurate method to determine electrical dosage in RUL ECT.

Magnetoelectric brain stimulation in the assessment of brain physiology and pathophysiology

OBJECTIVE

To review findings from transcranial magnetic stimulation (TMS)-induced motor evoked potentials in normal subjects, in various neurological diseases and with pharmacologic manipulation.

METHODS

MEDLINE was searched to identify pertinent articles and articles referenced therein were also reviewed.

RESULTS

TMS is a safe and non-invasive technique which has been used widely in the study of corticospinal and corticocortical connectivity as well as in the assessment of basal ganglia disorders, diffuse diseases, and neuropharmacology.

CONCLUSIONS

TMS motor measures have utility in examination of brain structure and function within and beyond the corticospinal tract. These measures have both research and clinical applications.

Vagus nerve stimulation (VNS) for treatment-resistant depressions: a multicenter study

BACKGROUND

Vagus Nerve Stimulation (VNS) delivered by the NeuroCybernetic Prosthesis (NCP) System was examined for its potential antidepressant effects.

METHODS

Adult outpatients (n = 30) with nonpsychotic, treatment-resistant major depressive (n = 21) or bipolar I (n = 4) or II (n = 5; depressed phase) disorders who had failed at least two robust medication trials in the current major depressive episode (MDE) while on stable medication regimens completed a baseline period followed by NCP System implantation. A 2-week, single-blind recovery period (no stimulation) was followed by 10 weeks of VNS.

RESULTS

In the current MDE (median length = 4.7 years), patients had not adequately responded to two (n = 9), three (n = 2), four (n = 6), or five or more (n = 13) robust antidepressant medication trials or electroconvulsive therapy (n = 17). Baseline 28-item Hamilton Depression Rating Scale (HDRS(28)) scores averaged 38.0. Response rates (> or =50% reduction in baseline scores) were 40% for both the HDRS(28) and the Clinical Global Impressions-Improvement index (score of 1 or 2) and 50% for the Montgomery-Asberg Depression Rating Scale. Symptomatic responses (accompanied by substantial functional improvement) have been largely sustained during long-term follow-up to date.

CONCLUSIONS

These open trial results suggest that VNS has antidepressant effects in treatment-resistant depressions.

Vagus nerve stimulation: a new tool for brain research and therapy

Biological psychiatry has a long history of using somatic therapies to treat neuropsychiatric illnesses and to understand brain function. These methods have included neurosurgery, electroconvulsive therapy, and, most recently, transcranial magnetic stimulation. Fourteen years ago researchers discovered that intermittent electrical stimulation of the vagus nerve produces inhibition of neural processes, which can alter brain electrical activity and terminate seizures in dogs. Since then, approximately 6000 people worldwide have received vagus nerve stimulation for treatment-resistant epilepsy. We review the neurobiology and anatomy of the vagus nerve and provide an overview of the vagus nerve stimulation technique. We also describe the safety and potential utility of vagus nerve stimulation as a neuroscience research tool and as a putative treatment for psychiatric conditions. Vagus nerve stimulation appears to be a promising new somatic intervention that may improve our understanding of brain function and has promise in the treatment of neuropsychiatric disorders.

Acute efficacy of ECT in the treatment of major depression in the old-old

OBJECTIVE

There are few data addressing the outcome of ECT for persons over 75 years of age. In a prospective, multisite study, the authors compared characteristics and treatment outcomes of adult (59 and younger), young-old (60 to 74 years), and old-old (75 and older) patients treated with ECT for major depression.

METHOD

At four hospitals, 268 patients with primary unipolar major depression and scores of at least 20 on the 24-item Hamilton Depression Rating Scale were treated with suprathreshold right unilateral or bilateral ECT in a standardized manner. Demographic variables, clinical characteristics, and short-term outcomes of the three groups were compared.

RESULTS

The demographic and clinical characteristics of the old-old patients were similar to those of the young-old patients, whereas both groups differed from the adult patients on these variables. Both older groups had significantly greater burdens from physical illness and global cognitive impairment at baseline than the adult subjects. Both older groups had shorter index depressive episodes and were less likely to have had inadequate responses to adequate medication trials before ECT. The older groups had higher seizure thresholds, but the three groups received similar courses of treatment. The adult patients experienced a significantly lower rate of ECT response (54%) than the young-old patients (73%), while the old-old patients had an intermediate rate of response (67%).

CONCLUSIONS

Despite a higher level of physical illness and cognitive impairment, even the oldest patients with severe major depression tolerate ECT in a manner similar to that for younger patients and demonstrate similar or better acute response.