Andrew Darrell Krystal

Journal article J Clin Psychiatry · 2004 Featured Publication A particular challenge in the treatment of insomnia is management of chronic insomnia, which occurs in a substantial portion of the population. A number of factors suggest the importance of identifying this condition as distinct from short-term insomnia in ... Link to item Cite

Sustained efficacy of eszopiclone over 6 months of nightly treatment: results of a randomized, double-blind, placebo-controlled study in adults with chronic insomnia.

Journal article Sleep · November 1, 2003 Featured Publication STUDY OBJECTIVES: To determine the long-term efficacy of eszopiclone in patients with chronic insomnia. DESIGN: Randomized, double-blind, multicenter, placebo-controlled. SETTING: Out-patient, with monthly visits. PATIENTS: Aged 21 to 69 years meeting DSM ... Full text Link to item Cite

Subtyping primary insomnia: is sleep state misperception a distinct clinical entity?

Journal article Sleep Med Rev · June 2003 Featured Publication Among the range of primary insomnia subtypes, those assigned such labels as subjective insomnia or sleep state misperception historically have been among the most intriguing yet challenging to understand and manage clinically. Such patients who produce see ... Full text Link to item Cite

Comparison of seizure duration, ictal EEG, and cognitive effects of ketamine and methohexital anesthesia with ECT.

Journal article J Neuropsychiatry Clin Neurosci · 2003 Featured Publication The authors retrospectively compared the seizure duration, ictal EEG, and cognitive side effects of ketamine and methohexital anesthesia with ECT. This comparison was carried out with data from consecutive index ECT treatments that occurred immediately bef ... Full text Link to item Cite

Insomnia in women.

Journal article Clin Cornerstone · 2003 Featured Publication Insomnia is a highly prevalent disorder that can lead to substantial impairments in quality of life and functional capacity. This condition occurs significantly more frequently in women than men. An important contributing factor is that insomnia can occur ... Full text Link to item Cite

NREM sleep EEG frequency spectral correlates of sleep complaints in primary insomnia subtypes.

Journal article Sleep · September 15, 2002 Featured Publication STUDY OBJECTIVES: To determine whether the frequency spectrum of the sleep EEG is a physiologic correlate of 1) the degree to which individuals with persistent primary insomnia (PPI) underestimate their sleep time compared with the traditionally scored pol ... Link to item Cite

The development and retrospective testing of an electroencephalographic seizure quality-based stimulus dosing paradigm with ECT.

Journal article J ECT · December 2000 Featured Publication The optimization of electroconvulsive therapy (ECT) stimulus dosing remains uncertain. Previous work suggests the potential utility of ictal EEG models of seizure adequacy, but such models have never been tested for their ability to improve the clinical do ... Full text Link to item Cite

Prediction of the utility of a switch from unilateral to bilateral ECT in the elderly using treatment 2 ictal EEG indices.

Journal article J ECT · December 2000 Featured Publication BACKGROUND: The choice of whether to administer nondominant unilateral (UL) or bilateral (BL) ECT remains controversial. METHODS: A study in which moderately suprathreshold UL nonresponders at treatment 6 were randomized to UL or BL ECT offered the opportu ... Full text Link to item Cite

ECT stimulus intensity: are present ECT devices too limited?

Journal article Am J Psychiatry · June 2000 Featured Publication OBJECTIVE: The maximum output charge for ECT devices is limited to 576 millicoulombs in the United States, although there are no data ensuring that this limit will allow consistently effective treatments. The authors examined whether this limit has a negat ... Full text Link to item Cite

EEG effects of ECT: implications for rTMS.

Journal article Depress Anxiety · 2000 Featured Publication Electroconvulsive therapy (ECT) involves the use of electrical stimulation to elicit a series of generalized tonic-clonic seizures for therapeutic purposes and is the most effective treatment known for major depression. These treatments have significant ne ... Full text Link to item Cite

Stationarity and redundancy of multichannel EEG data recorded during generalized tonic-clonic seizures.

Journal article Brain Topogr · 2000 Featured Publication To improve our understanding of the physiology of generalized tonic-clonic (GTC) seizures, we have investigated the stationarity and redundancy of 21-electrode EEG data recorded from ten patients during GTC seizures elicited by electroconvulsive therapy (E ... Full text Link to item Cite

New methods of time series analysis of non-stationary EEG data: eigenstructure decompositions of time varying autoregressions.

Journal article Clin Neurophysiol · December 1999 Featured Publication OBJECTIVE: Those who analyze EEG data require quantitative techniques that can be validly applied to time series exhibiting ranges of non-stationary behavior. Our objective is to introduce a new analysis technique based on formal non-stationary time series ... Full text Link to item Cite

Zolpidem for persistent insomnia in SSRI-treated depressed patients.

Journal article J Clin Psychiatry · October 1999 Featured Publication BACKGROUND: Depressed individuals effectively treated with selective serotonin reuptake inhibitors (SSRIs) often report persistent insomnia and require adjunctive sleep-promoting therapy. METHOD: Men (N = 40) and women (N = 150) with a mean age of 41.6 yea ... Full text Link to item Cite

EEG correlates of the response to ECT: a possible antidepressant role of brain-derived neurotrophic factor.

Journal article J ECT · March 1999 Featured Publication Studies on the relationship of electroencephalographic (EEG) data to the therapeutic response to electroconvulsive therapy (ECT) have been carried out since the 1940s, but for many years they did not yield any consistent correlates. Recent studies, however ... Link to item Cite

The use of flumazenil in the anxious and benzodiazepine-dependent ECT patient.

Journal article J ECT · March 1998 Featured Publication Many patients who receive electroconvulsive therapy (ECT) are benzodiazepine dependent or are anxious and require benzodiazepine drugs. Because these agents may diminish the therapeutic effectiveness of ECT, we explored the dosing, safety, and efficacy of ... Link to item Cite

Low-dimensional chaos in bipolar disorder?

Journal article Arch Gen Psychiatry · March 1998 Featured Publication Full text Link to item Cite

Changes in seizure threshold over the course of electroconvulsive therapy affect therapeutic response and are detected by ictal EEG ratings.

Journal article J Neuropsychiatry Clin Neurosci · 1998 Featured Publication Therapeutic effectiveness of electroconvulsive therapy is influenced by the degree to which the stimulus intensity exceeds the seizure threshold. However, the threshold rises variably over the treatment course, confounding maintenance of desired relative s ... Full text Link to item Cite

The largest Lyapunov exponent of the EEG during ECT seizures as a measure of ECT seizure adequacy.

Journal article Electroencephalogr Clin Neurophysiol · December 1997 Featured Publication Attributes of the electroencephalogram (EEG) recorded during electroconvulsive therapy (ECT) seizures appear promising for decreasing the uncertainty that exists about how to define a therapeutically adequate seizure. In the present report we study whether ... Full text Link to item Cite

Neuropsychiatric considerations in the use of electroconvulsive therapy.

Journal article J Neuropsychiatry Clin Neurosci · 1997 Featured Publication ECT is an effective and rapidly acting treatment for certain major psychiatric disorders, even in patients with neurologic illness. Further, in some cases the neurologic illness itself also responds to ECT. Patients with some types of neurologic illness ma ... Full text Link to item Cite

A comparison of EEG signal dynamics in waking, after anesthesia induction and during electroconvulsive therapy seizures.

Journal article Electroencephalogr Clin Neurophysiol · August 1996 Featured Publication Evidence suggests that quantitative dynamical measures of electroencephalogram (EEG) signals are more appropriate for characterizing the differences between states in an individual rather than as absolute indices. One such measure, the largest Lyapunov exp ... Full text Link to item Cite

The empirical identification of insomnia subtypes: a cluster analytic approach.

Journal article Sleep · June 1996 Featured Publication Over the past 15 years, there has been considerable debate concerning the extent to which insomnia patients can be classified into diagnostic subtypes. Despite this debate, relatively little research has been conducted to empirically determine whether natu ... Link to item Cite

Effect of ECT treatment number on the ictal EEG.

Journal article Psychiatry Res · May 17, 1996 Featured Publication Recent evidence suggests that attributes of the ictal electroencephalogram (EEG) may be clinically useful for estimating the extent to which the electroconvulsive therapy (ECT) stimulus exceeds the seizure threshold (relative stimulus intensity). Such a to ... Full text Link to item Cite

The relative ability of three ictal EEG frequency bands to differentiate ECT seizures on the basis of electrode placement, stimulus intensity, and therapeutic response.

Journal article Convuls Ther · March 1996 Featured Publication Ictal EEG indices show promise for separating individual ECT seizures on the basis of treatment electrode placement (ELPL), relative stimulus intensity (Dose), and expected therapeutic response. One factor impeding the effective clinical implementation of ... Link to item Cite

ECT seizure duration: reliability of manual and computer-automated determinations.

Journal article Convuls Ther · September 1995 Featured Publication Reliable monitoring of electroencephalographic (EEG) and electromyographic electroconvulsive therapy (ECT) seizure duration has become important as these assessments have become a routine part of the clinical practice of ECT. In this regard, accurate autom ... Link to item Cite

Seizure threshold in electroconvulsive therapy (ECT) II. The anticonvulsant effect of ECT.

Journal article Biol Psychiatry · June 1, 1995 Featured Publication To measure the anticonvulsant effects of a course of electroconvulsive therapy (ECT), we used a flexible stimulus dosage titration procedure to estimate seizure threshold at the first and sixth ECT treatments in 62 patients with depression who were undergo ... Full text Link to item Cite

Seizure threshold in electroconvulsive therapy: I. Initial seizure threshold.

Journal article Biol Psychiatry · May 15, 1995 Featured Publication We measured initial seizure threshold by means of a structured stimulus dosage titration procedure in a clinical sample of 111 depressed patients undergoing brief-pulse, constant-current electroconvulsive therapy (ECT). Initial seizure threshold was approx ... Full text Link to item Cite

Ambulatory cassette polysomnography: findings from a large cohort of drug-free insomnia patients.

Journal article J Clin Neurophysiol · May 1995 Featured Publication Technology for conducting ambulatory polysomnography (APSG) has been available for more than a decade, but relatively few studies have used this technology to study the sleep of subjects in their usual home sleeping environments. Herein we suggest the usef ... Link to item Cite

The ictal EEG as a marker of adequate stimulus intensity with unilateral ECT.

Journal article J Neuropsychiatry Clin Neurosci · 1995 Featured Publication Relative stimulus intensity above seizure threshold has been shown to affect therapeutic outcome with unilateral ECT. The authors sought to explore whether a multivariate ictal EEG model would permit ongoing clinical assessment of this parameter. Twenty-fi ... Full text Link to item Cite

ECT seizure therapeutic adequacy.

Journal article Convuls Ther · June 1994 Featured Publication From the beginnings of convulsive therapy, the need for some way to assess the therapeutic adequacy of individual treatments has been apparent. Recent work suggests that seizure therapeutic adequacy and adverse effects are dependent on the extent to which ... Link to item Cite

The present use of electroconvulsive therapy.

Journal article Annu Rev Med · 1994 Featured Publication Physicians attempting to treat certain severe mental disorders have recently shown renewed interest in electroconvulsive therapy (ECT). A number of technical innovations have made ECT safer, as well as more effective. These innovations include oxygenation, ... Full text Link to item Cite

The effects of ECT stimulus dose and electrode placement on the ictal electroencephalogram: an intraindividual crossover study.

Journal article Biol Psychiatry · December 1, 1993 Featured Publication Recent evidence suggests that electroconvulsive therapy (ECT) efficacy depends upon both electrode placement and the degree to which stimulus dosage exceeds seizure threshold (T), and not simply on surpassing a minimum seizure duration as has been assumed. ... Full text Link to item Cite

EEG evidence of more "intense" seizure activity with bilateral ECT.

Journal article Biol Psychiatry · March 15, 1992 Featured Publication Full text Link to item Cite

Ambulatory polysomnography: technical aspects and normative values.

Journal article J Clin Neurophysiol · January 1992 Featured Publication Ambulatory polysomnographic (APSG) assessment of sleep disorders is now possible, but the technique of APSG is sufficiently different from in-laboratory PSG that normative data from in-laboratory PSG may not apply to APSG. This paper reviews the technical ... Link to item Cite

The electrophysiology of ECT: relevance to mechanism of action.

Journal article Clin Neuropharmacol · 1992 Featured Publication Full text Link to item Cite

The monitoring and management of electrically induced seizures.

Journal article Psychiatr Clin North Am · December 1991 Featured Publication Because induced seizures have such a fundamental influence on both beneficial and adverse effects associated with ECT, it is crucial that they be monitored as effectively as possible. In practice this process involves a combination of both motor and EEG mo ... Link to item Cite

Shared features of neuroleptic malignant syndrome and alcohol abuse complications.

Journal article J Clin Psychiatry · December 1990 Featured Publication Link to item Cite

Differential diagnosis and pathophysiology of Cushing's syndrome and primary affective disorder.

Journal article J Neuropsychiatry Clin Neurosci · 1990 Featured Publication Most patients with major depression have increased 24-hour urinary free cortisol and cortisol nonsuppression after dexamethasone administration, which are cornerstones of a diagnosis of Cushing's syndrome. Similarly, Cushing's syndrome patients often suffe ... Full text Link to item Cite