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P E Keck

Publications and source records attributed to P E Keck.

At least 19 recordsLinked to original sources
PubMed2002

Segmental linkage disequilibrium within the dopamine transporter gene.

The dopamine transporter gene (DAT) has been implicated in a variety of disorders, including bipolar disorder, attention-deficit hyperactivity disorder, cocaine-induced paranoia, Tourette's syndrome, and Parkinson's disease. As no clear functional polymorphism has been identified to date, studies rely on linkage disequilibrium (LD) to assess the possible genetic contribution of DAT to the various disorders. A better understanding of the complex structure of LD across the gene is thus critical for an accurate interpretation of the results of such studies, and may facilitate the mapping of the actual functional variants. In the process of characterizing the extent of variation within the DAT gene, we have identified a number of single nucleotide polymorphisms (SNPs) suitable for LD studies, 14 of which have been analyzed, along with a 3' repeat polymorphism, in a sample of 120 parent-proband triads. Calculations of pairwise LD between the SNPs in the parental haplotypes revealed a high degree of LD (P < 0.00001) in the 5' (distal promoter through intron 6) and 3' (exon 9 through exon 15) regions of DAT. This segmental LD pattern is maintained over approximately 27 kb and 20 kb in these two regions, respectively, with very little significant LD between them, possibly due to the presence of a recombination hotspot located near the middle of the gene. These analyses of the DAT gene thus reveal a complex structure resulting from both recombination and mutation, knowledge of which may be invaluable to the design of future studies.

Dopamine Plasma Membrane Transport Proteins↗
PubMed2002

What makes a drug a primary mood stabilizer?

The term 'mood stabilizer' has been applied to a number of medications for the treatment of patients with bipolar disorder. The operational definition of the properties of a mood-stabilizing medication has varied according to the properties of specific medications and the clinical characteristics of the illness. Randomized controlled trials of agents accepted or proposed as mood stabilizers are reviewed to marshall the available evidence in support of this claim. In addition, potential pharmacological mechanisms underlying mood-stabilizing effects of established compounds are reviewed.

Affect↗
PubMed2001

Evidence for linkage disequilibrium between the dopamine transporter and bipolar disorder.

A role for the dopamine transporter (DAT) in bipolar disorder is implicated by several lines of pharmacological evidence, as well as suggestive evidence of linkage at this locus, which we have reported previously. In an attempt to identify functional mutations within DAT contributing a susceptibility to bipolar disorder, we have screened the entire coding region, as well as significant portions of the adjacent non-coding sequence. Though we have not found a definitive functional mutation, we have identified a number of single nucleotide polymorphisms (SNPs) that span the gene from the distal promoter through exon 15. Of the 39 SNPs that are suitable for linkage disequilibrium (LD) studies, 14 have been analyzed by allele-specific PCR in a sample of 50 parent-proband triads with bipolar disorder. A haplotyped marker comprised of five SNPs, spanning the region between exon 9 and exon 15, was constructed for each individual, and transmission/disequilibrium test (TDT) analysis revealed this haplotype to be in linkage disequilibrium with bipolar disorder (allele-wise TDT p = 0.001, genotype-wise TDT p = 0.0004). These data replicate our previous finding of linkage to markers within and near DAT in a largely different family set, and provide further evidence for a role of DAT in bipolar disorder. Published 2001 Wiley-Liss. Inc.

Alleles↗
PubMed2001

Multivariate logistic regression for familial aggregation of two disorders. II. Analysis of studies of eating and mood disorders.

Family studies have suggested that eating disorders and mood disorders may coaggregate within families. Previous studies, however, have been limited by use of univariate modeling techniques and failure to account for the correlation of observations within families. To provide a more efficient analysis and to illustrate multivariate logistic regression models for familial aggregation of two disorders, the authors analyzed pooled data from two previously published family studies (conducted in Massachusetts in 1984-1986 and 1986-1987) by using multivariate proband predictive and family predictive models. Both models demonstrated a significant familial aggregation of mood disorders and familial coaggregation of eating and mood disorders. The magnitude of the coaggregation between eating and mood disorders was similar to that of the aggregation of mood disorders. Similar results were obtained with alternative models, including a traditional univariate proband predictive model. In comparison with the univariate model, the multivariate models provided greater flexibility, improved precision, and wider generality for interpreting aggregation effects.

Family↗
PubMed2001

Bipolar disorder.

Bipolar disorder (manic-depressive illness) is a common, recurrent, and severe psychiatric disorder that affects 1% to 3% of the US population. The illness is characterized by episodes of mania, depression, or mixed states (simultaneously occurring manic and depressive symptoms). Bipolar disorder frequently goes unrecognized and untreated for many years without clinical vigilance. New screening tools have been developed to assist physicians in making the diagnosis. Fortunately, several medications are now available to treat the acute mood episodes of bipolar disorder and to prevent further episodes with maintenance treatment.

Anticonvulsants↗
PubMed2001

Olanzapine versus haloperidol in schizoaffective disorder, bipolar type.

BACKGROUND: The present analysis was performed on data from a subsample of patients with schizoaffective disorder, bipolar type, who participated in a multicenter, double-blind study comparing olanzapine to haloperidol. METHODS: Patients with schizoaffective disorder bipolar type, characterized as currently manic, mixed, depressed, or euthymic, were assessed weekly for 6 weeks during treatment with either olanzapine or haloperidol. Manic symptoms were measured using the sum of six items of the BPRS, and depressive symptoms were assessed using the Montgomery-Asberg Depression Rating Scale. In addition, cognitive functioning was measured using the sum of seven items from the PANSS. Repeated measures analyses were performed using random coefficients regression of the serial measurement of manic, cognitive, and depressive symptoms. RESULTS: A significant treatment difference was detected overall, indicating that olanzapine was significantly more effective than haloperidol in reducing symptoms of depression and improving patients' cognitive symptoms. The superiority of olanzapine over haloperidol in the reduction of manic symptoms did not reach statistical significance (P=.052). The greatest improvement in both manic and cognitive symptoms was seen in the olanzapine-treated 'currently manic' subgroup, and least improvement in the haloperidol-treated 'euthymic' subgroup. Depressive symptoms were most improved in the olanzapine-treated 'depressed' subgroup, and least improved in the corresponding haloperidol subgroup. CONCLUSIONS: Overall, olanzapine was superior to haloperidol with respect to thymoleptic effects in patients with schizoaffective disorder, bipolar type.

Administration, Oral↗
PubMed2001

The Stanley Foundation Bipolar Treatment Outcome Network. I. Longitudinal methodology.

The NIMH-Stanley Foundation Bipolar Treatment Outcome Network, a multisite clinical trials network, has been established to address many of the neglected areas of research in bipolar illness. The Network was designed so that it would be able to conduct randomized clinical trials at several different levels of methodologic rigor (blinded and open-label) both in academic and community practice settings in order to better assess long-term efficacy of existing treatments and develop new ones. In this fashion, large numbers of representative patients with bipolar disorder have been enrolled with an additional focus of elucidating possible clinical and biological predictors of treatment response. The unique focus of the Network is its systematic longitudinal approach to illness so that patients can be assessed comprehensively over the long-term in sequential randomized clinical trials at critical clinical decision points where data on relative efficacy are inadequate. Bipolar I and bipolar II patients with a range of illness variants and comorbidities are included. Daily prospective ratings of severity of mania and depression and associated degree of functional impairment are completed on the NIMH-Life Chart Method and a modified Clinical Global Impressions Scale for Bipolar Illness (CGI-BP) is utilized. More detailed cross-sectional ratings for depression (Inventory of Depressive Symptomatology), mania (Young Mania Rating Scale), and psychosis (Positive and Negative Syndrome Scale) are additionally used at academic centers. This article describes the rationale for the Network, its guiding principles, methods, and study design to systematically assess the highly variable course of bipolar illness and its response to current and future treatments.

Bipolar Disorder↗
PubMed2001

The Stanley Foundation Bipolar Treatment Outcome Network. II. Demographics and illness characteristics of the first 261 patients.

BACKGROUND: Since recent NIMH Bipolar Disorder Workshops highlighted the dearth of longitudinal and controlled studies of bipolar illness, the Stanley Foundation Bipolar Network (SFBN) has recruited a large cohort of patients with bipolar disorder to begin to address these issues. This report describes the demographics and course of illness characteristics of this study population. METHODS: The first 261 outpatients to be diagnosed by the Structured Clinical Interview for DSM-IV (SCID) and complete a detailed patient and a brief clinician questionnaire are described. All patients met DSM-IV criteria for bipolar I (n=211), bipolar II (n=42), or NOS (n=5) or schizoaffective (n=3), bipolar type. Chi-square and t-tests were used to examine statistically significant associations among important demographic and descriptive items. RESULTS: The general demographic and illness characteristics were similar to those in many bipolar clinical samples and not dissimilar from those reported in epidemiological surveys. The majority of patients had been hospitalized, with almost half reporting a worsening of illness over time, and two-thirds were not asymptomatic between episodes. First treatment for patients had been delayed by an average of 10 years from illness onset (by SCID). Almost a third of patients had attempted suicide at least once, and 30% reported current suicidal ideation at study entry. A total of 62% reported moderate to severe impact of the illness on occupational functioning. Early onset bipolar illness (< or =17 years old) was associated with increased frequency of mood switches, worsening course of illness, and history of early abuse (physical, verbal, or sexual). CONCLUSION: The SFBN represents a sample of predominantly BP I patients largely recruited from the community who will be followed in detail longitudinally, participate in clinical trials, and thus help advance our understanding and treatment of this life-threatening medical disorder. While there is a broad range of illness characteristics and severity, the majority of patients have been severely impacted by their illness despite the availability of multiple conventional treatment approaches in the community. These data further underscore the need for development of new and earlier treatment interventions. LIMITATION: The SFBN population is limited by the lack of random selection and represents a cohort willing to be treated and followed intensively in academic tertiary referral centers. While its characteristics are similar to many clinical study populations, the generalizability to non-clinic populations remains uncertain.

Activities of Daily Living↗
PubMed2001

An open trial of olanzapine in the treatment of patients with psychotic depression.

Compared to major depression without psychosis, psychotic depression often responds poorly to treatment with tricyclic antidepressants alone. Atypical antipsychotics, which appear to possess thymoleptic properties, may represent a new treatment alternative for patients with psychotic mood disorders. This open-label, pilot study evaluated the efficacy of olanzapine monotherapy in patients with psychotic depression. Seven inpatients who met DSM-IV criteria for a major depressive episode (unipolar) with psychotic features participated in a 10-week open-label trial of olanzapine 10-20 mg/day. The Hamilton Rating Scale for Depression (HRSD), the Scale for the Assessment of Positive Symptoms (SAPS), and the Clinical Global Impression Scale (CGI) were performed at each visit to evaluate clinical response. Four out of the 5 study completers responded during the trial. Overall, there was a statistically significant change between baseline and final visit on the SAPS, HRSD, and the CGI Scale (p < .001). The results of this pilot study suggest that olanzapine may be an effective treatment for some patients with unipolar psychotic depression. However, these observations require replication in randomized, controlled trials.

Adult↗
PubMed2001

A pilot study of rapid lithium administration in the treatment of acute mania.

OBJECTIVES: The use of rapid lithium dosage administration, a strategy that could lead to rapid improvement in mania, has been largely unexamined. In this open-label, pilot, acute-treatment study, we sought to determine the safety and tolerability of lithium administered at 20 mg/ kg/day. A secondary aim was to provide preliminary data regarding the efficacy of this strategy in ameliorating manic, depressive, and psychotic symptoms. METHODS: Fifteen patients hospitalized with DSM-IV bipolar disorder, manic or mixed, and who provided written informed consent, received lithium 20 mg/kg/day for up to 10 days. Patients were evaluated for adverse effects daily. Lithium levels were obtained on days 2, 3, 4, 5, 7, and 10 or at study termination. Electrocardiograms (EKGs) were performed at baseline and on days 1-5, 7, and 10 or at study termination. Symptomatic improvement was assessed daily using the Young Mania Rating Scale, 24-item Hamilton Depression Rating Scale, and the Scale for Assessment of Positive Symptoms (SAPS). RESULTS: Five of the 15 patients completed the 10-day study period. Two patients dropped out due to adverse events. Seven patients did not complete the inpatient trial because of improvement sufficient to allow hospital discharge. All patients achieved serum lithium concentrations > or =0.6 mEq/L after 1 day of treatment; the mean + SD concentration on day 5 was 1.1 (+/- 0.1) mEq/L on day 5. There were significant reductions from baseline to endpoint on all rating scales, except the SAPS bizarre behavior subscale. CONCLUSIONS: These pilot data suggest that lithium 20 mg/kg/day was well tolerated and that this strategy may produce rapid improvement in affective and psychotic symptoms. These impressions require confirmation in double-blind, randomized trials.

Acute Disease↗
PubMed2001

Ziprasidone in the short-term treatment of patients with schizoaffective disorder: results from two double- blind, placebo-controlled, multicenter studies.

This study assessed the efficacy of ziprasidone for the treatment of schizoaffective disorder. Data were taken from subsets of patients with schizoaffective disorder, derived from two separate double-blind, placebo-controlled, parallel-group, multicenter studies. A total of 115 hospitalized patients with an acute episode of schizoaffective disorder were randomly assigned to receive either fixed oral doses of ziprasidone 40 mg/day (N = 16), 80 mg/day (N = 18), 120 mg/day (N = 22), 160 mg/day (N = 25), or placebo (N = 34) for 4 to 6 weeks. Mean baseline-to-endpoint changes in Brief Psychiatric Rating Scale (BPRS) total, BPRS Core, Clinical Global Impressions Severity scale (CGI-S), BPRS Depressive, BPRS Manic, and Montgomery-Asberg Depression Rating Scale total scores were compared between the placebo and ziprasidone groups. Neurological (Simpson-Angus, Barnes Akathisia, Abnormal Involuntary Movement Scale [AIMS]) and other side effects were also assessed. Significant dose-related improvements on all primary efficacy variables (BPRS total, BPRS Core, CGI-S) and for BPRS Manic items were observed with ziprasidone treatment in a combined analysis of data from both studies (p < or = 0.01). Ziprasidone 160 mg/day was significantly more effective than placebo in improving mean BPRS total, BPRS Core, BPRS Manic, and CGI-S scores (p < 0.05). At 120 mg/day, ziprasidone was significantly more effective than placebo in improving mean CGI-S scores (p < 0.05). The incidence of individual adverse events was generally low in all treatment groups and was not dose-related. In addition, no significant differences were observed between baseline-to-endpoint mean changes in Simpson-Angus and AIMS scores with placebo or ziprasidone 40 to 160 mg/day. These results suggest that ziprasidone may have efficacy in the treatment of affective as well as psychotic symptoms of schizoaffective disorder, with a low side-effect burden.

Adolescent↗
PubMed2001

A pilot study of topiramate as monotherapy in the treatment of acute mania.

This small-scale pilot study was performed to grossly document safety and any evidence of efficacy of topiramate in bipolar disorder. Ten patients hospitalized for acute mania were given open-label topiramate monotherapy for up to 28 days. The mean Young Mania Rating Scale (YMRS) score decreased from 32 (range, 26-40) at baseline to 22 (range, 2-40) at the end of the study. Five patients exhibited evidence of moderate to marked improvement, three subjects had at least a 50% reduction in YMRS scores, and the other two patients experienced an improvement of 25% to 49% on the YMRS. The preliminary findings of this small series suggest that topiramate may be effective in acute mania. Double-blind controlled trials are now needed to further investigate the efficacy and safety of topiramate in bipolar disorder.

Adult↗
PubMed2001

A double-blind, randomized, prospective evaluation of the efficacy and safety of risperidone versus haloperidol in the treatment of schizoaffective disorder.

The relative efficacy and safety of risperidone versus haloperidol in the treatment of schizoaffective disorder was studied. Sixty-two patients (29 depressed type; 33 bipolar type) entered a three-site, randomized, double-blind, 6-week trial of risperidone (up to 10 mg/day) or haloperidol (up to 20 mg/day). Trained raters assessed baseline, weekly, and end-of-study levels of psychopathology with the Positive and Negative Syndrome Scale (PANSS), the 24-item Hamilton Rating Scale for Depression (HAM-D-24) and the Clinician-Administered Rating Scale for Mania (CARS-M). The authors were unable to statistically distinguish between risperidone and haloperidol in the amelioration of psychotic and manic symptoms. In addition, there was no difference in worsening of mania between the two agents in either subgroup (i.e., depressed or bipolar subgroups). For the total PANSS, risperidone produced a mean decrease of 16 points from baseline compared with a 14-point decrease with haloperidol. For the total CARS-M scale, risperidone and haloperidol produced mean change scores of 5 and 8 points, respectively, and for the CARS-M Mania subscale, 3 and 7 points, respectively. Additionally, risperidone produced a mean decrease of 13 points from the baseline 24-item HAM-D, compared with an 8-point decrease with haloperidol. In those patients who had more severe depressive symptoms (i.e., HAM-D baseline score >20), risperidone produced at least a 50% mean improvement in 12 (75%) of 16 patients in comparison to 8 (38%) of 21 patients receiving haloperidol. Haloperidol produced significantly more extrapyramidal side effects and resulted in more dropouts caused by any side effect. There was no difference between risperidone and haloperidol in reducing both psychotic and manic symptoms in this group of patients with schizoaffective disorder. Risperidone did not demonstrate a propensity to precipitate mania and was better tolerated than haloperidol. In those subjects with higher baseline HAM-D scores (i.e., >20), risperidone produced a greater improvement in depressive symptoms than haloperidol.

Adult↗
PubMed2001

Axis I psychiatric comorbidity and its relationship to historical illness variables in 288 patients with bipolar disorder.

OBJECTIVE: Bipolar disorder often co-occurs with other axis I disorders, but little is known about the relationships between the clinical features of bipolar illness and these comorbid conditions. Therefore, the authors assessed comorbid lifetime and current axis I disorders in 288 patients with bipolar disorder and the relationships of these comorbid disorders to selected demographic and historical illness variables. METHOD: They evaluated 288 outpatients with bipolar I or II disorder, using structured diagnostic interviews and clinician-administered and self-rated questionnaires to determine the diagnosis of bipolar disorder, comorbid axis I disorder diagnoses, and demographic and historical illness characteristics. RESULTS: One hundred eighty-seven (65%) of the patients with bipolar disorder also met DSM-IV criteria for at least one comorbid lifetime axis I disorder. More patients had comorbid anxiety disorders (N=78, 42%) and substance use disorders (N=78, 42%) than had eating disorders (N=9, 5%). There were no differences in comorbidity between patients with bipolar I and bipolar II disorder. Both lifetime axis I comorbidity and current axis I comorbidity were associated with earlier age at onset of affective symptoms and syndromal bipolar disorder. Current axis I comorbidity was associated with a history of development of both cycle acceleration and more severe episodes over time. CONCLUSIONS: Patients with bipolar disorder often have comorbid anxiety, substance use, and, to a lesser extent, eating disorders. Moreover, axis I comorbidity, especially current comorbidity, may be associated with an earlier age at onset and worsening course of bipolar illness. Further research into the prognostic and treatment response implications of axis I comorbidity in bipolar disorder is important and is in progress.

Adult↗
PubMed2001

CSF norepinephrine concentrations in posttraumatic stress disorder.

OBJECTIVE: Despite evidence of hyperresponsive peripheral and central nervous system (CNS) noradrenergic activity in posttraumatic stress disorder (PTSD), direct measures of CNS norepinephrine in PTSD have been lacking. The goal of this study was to determine serial CSF norepinephrine levels in patients with PTSD. METHOD: CSF samples were obtained serially over a 6-hour period in 11 male combat veterans with chronic PTSD and eight healthy men through an indwelling subarachnoid catheter. Thus the authors were able to determine hourly CSF norepinephrine concentrations under baseline (unstressed) conditions. Severity of the patients' PTSD symptoms was assessed with the Clinician-Administered PTSD Scale. RESULTS: CSF norepinephrine concentrations were significantly higher in the men with PTSD than in the healthy men. Moreover, CSF norepinephrine levels strongly and positively correlated with the severity of PTSD symptoms. Plasma norepinephrine concentrations showed no significant relationship with the severity of PTSD symptoms. CONCLUSIONS: These findings reveal the presence of greater CNS noradrenergic activity under baseline conditions in patients with chronic PTSD than in healthy subjects and directly link this pathophysiologic observation with the severity of the clinical posttraumatic stress syndrome.

Adult↗
PubMed2001

The Stanley Foundation Bipolar Network. I. Rationale and methods.

BACKGROUND: The Stanley Foundation Bipolar Network (SFBN) was created to address the paucity of help studies in bipolar illness. AIMS: To describe the rationale and methods of the SFBN. METHOD: The SFBN includes five core sites and a number of affiliated sites that have adopted consistent methodology for continuous longitudinal monitoring of patients. Open and controlled studies are performed as patients' symptomatology dictates. RESULTS: The reliability of SFBN raters and the validity of the rating instruments have been established. More than 500 patients are in continuous daily longitudinal follow-up. More than 125 have been randomised to one of three of the newer antidepressants (bupropion, sertraline and venlafaxine) as adjuncts in a study of mood stabilizers and 93 to omega-3 fatty acids. A number of open clinical case series have been published. CONCLUSIONS: Well-characterised patients are followed in a detailed continuous longitudinal fashion in both opportunistic case series and double-blind, randomised controlled trials with reliable and validated measures.

Antimanic Agents↗
PubMed2001

Ziprasidone: a new atypical antipsychotic.

This paper reviews the clinical pharmacology, efficacy and safety of the new atypical antipsychotic, ziprasidone. All published citations regarding ziprasidone were retrieved and reviewed using a MEDLINE search (completed for citations to early 2001). In addition, abstracts from recent scientific meetings presenting data not yet published were reviewed. Like other new antipsychotic medications, ziprasidone fits the profile of an atypical agent, exerting efficacy in positive and negative symptoms of psychosis, as well as affective symptoms, with a low risk of neurological and neuroendocrinological side effects. Unlike newer agents, it does not appear to be associated with weight gain in most patients.

Antipsychotic Agents↗