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Biomedical subjects

Michael Davidson

Publications and source records attributed to Michael Davidson.

At least 37 records · Page 2Linked to original sources
PubMed2005

Treatment of cognitive impairment in early psychosis: a comparison of risperidone and haloperidol in a large long-term trial.

OBJECTIVE: Cognitive impairment is a major determinant of functional outcome in schizophrenia. Treatment of cognitive impairment at the time of the first episode may have the potential to change functional outcomes of the illness. This study examined changes associated with treatment with risperidone compared with haloperidol in aspects of cognitive functioning known to be associated with functional outcomes. The study was conducted in a large group of patients experiencing their first episode of schizophrenia. METHOD: Cognitive assessments were conducted in 533 patients experiencing their first episode of schizophrenia or a related psychosis who had been randomly assigned to receive low doses of risperidone or haloperidol. The cognitive assessments were repeated at several different follow-up intervals; 359 patients were reexamined at the 3-month follow-up. The assessments included examinations of verbal and visuospatial episodic memory, vigilance, executive functioning, processing speed, and verbal fluency. Patients' clinical symptoms were also rated with the Positive and Negative Syndrome Scale. RESULTS: Improvements from baseline were found in the risperidone-treated patients for episodic memory, verbal fluency, vigilance, executive functioning, and visuomotor speed. Haloperidol-treated patients also showed improvements from baseline in episodic memory, vigilance, and visuomotor speed but not in executive functioning or verbal fluency. Comparison of differential treatment effects on a composite measure of cognitive functioning found that risperidone was significantly more beneficial than haloperidol after 3 months of treatment. Changes in Positive and Negative Syndrome Scale scores were correlated overall with improvement in the haloperidol-treated patients but not in the risperidone-treated patients. CONCLUSIONS: Treatment with risperidone at the time of the first episode of schizophrenia is associated with wide-ranging improvements in cognitive functioning. Overall improvement is significantly greater with risperidone than with haloperidol. Further, cognitive improvement associated with treatment with risperidone was not influenced by changes in symptoms, but that relationship was significant in haloperidol-treated patients.

Adult↗
PubMed2005

Risperidone and haloperidol in first-episode psychosis: a long-term randomized trial.

OBJECTIVE: The first episode of psychotic illness is a key intervention point. The initial experience with medication can affect willingness to accept treatment. Further, relapse prevention is a treatment cornerstone during the first years of illness because active psychotic illness may affect lifetime outcomes. Thus, initial treatment of active symptoms and subsequent relapse prevention are central goals of pharmacotherapy. This study compared long-term effectiveness of risperidone versus haloperidol in first-episode psychosis patients. METHOD: First-episode psychosis patients (N=555, mean age=25.4 years) participated in a double-blind, randomized, controlled flexible-dose trial that compared risperidone (mean modal dose=3.3 mg) and haloperidol (mean modal dose=2.9 mg). The median treatment length was 206 days (maximum=1,514). RESULTS: Positive and Negative Syndrome Scale scores and Clinical Global Impression ratings improved significantly relative to baseline, with no significant differences between groups. Three-quarters of the patients achieved initial clinical improvement, defined as >20% reduction in total Positive and Negative Syndrome Scale score. However, among those who achieved clinical improvement, 42% of the risperidone group experienced a relapse compared with 55% of the haloperidol group. The median time to relapse was 466 days for risperidone-treated subjects and 205 days for those given haloperidol. These differences were statistically significant based on Kaplan-Meier survival analysis. Adverse effects distinguished the treatments: there were significantly more extrapyramidal signs and symptoms and adjunctive medication use in the haloperidol group and greater prolactin elevation in the risperidone group. There was less weight gain with haloperidol initially but no significant differences between groups at endpoint. CONCLUSIONS: Relatively low doses of antipsychotic drugs lead to significant symptom amelioration in the majority of first-episode psychosis patients. In the long term, risperidone prevents relapse in more patients and for a longer time and also induces less abnormal movements than haloperidol.

Adult↗
PubMed2005

Time for a shift in focus in schizophrenia: from narrow phenotypes to broad endophenotypes.

Many manifestations of mental illness, risk factors, course and even response to treatment are shared by several diagnostic groups. For example, cognitive and social impairments are present to some degree in most DSM and ICD diagnostic groups. The idea that diagnostic boundaries of mental illness, including schizophrenia, have to be redefined is reinforced by recent findings indicating that on the one hand multiple genetic factors, each exerting a small effect, come together to manifest as schizophrenia, and on the other hand, depending on interaction with the environment, the same genetic variations can present as diverse clinical phenotypes. Rather than attempting to find a unitary biological explanation for a DSM construct of schizophrenia, it would be reasonable to deconstruct it into the most basic manifestations, some of which are common with other DSM constructs, such as cognitive or social impairment, and then investigate the biological substrate of these manifestations.

Cognition Disorders↗
PubMed2005

Torcetrapib/atorvastatin combination therapy.

Elevated blood levels of low-density lipoprotein cholesterol (LDL-C) are associated with an increased risk for atherosclerotic coronary heart disease (CHD). Atorvastatin is a statin drug that inhibits 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (the rate-limiting step of cholesterol production) and primarily lowers LDL-C levels. Atorvastatin has also been shown to significantly reduce CHD events. However, as with all statins (and all other monotherapy lipid-altering drugs), atorvastatin alone reduces the risk of CHD in only a minority of patients relative to placebo. Conversely, it is low levels of high-density lipoprotein cholesterol that are associated with increased CHD risk. Torcetrapib is a cholesteryl ester transfer protein inhibitor that primarily raises high-density lipoprotein cholesterol levels, and cholesteryl ester transfer protein inhibition has generally been shown to reduce atherosclerosis in rabbits. Taken together, atorvastatin and torcetrapib provide striking improvements in lipid levels, and complementary actions upon important lipid parameters. This review examines the chemistry, mechanism of action, pharmacokinetics, metabolism, safety/tolerability and efficacy of the combination torcetrapib/atorvastatin agent that is currently in development and that provides complementary lipid benefits towards the goal of reducing CHD risk beyond that of atorvastatin alone.

Animals↗
PubMed2005

A genetic and epidemiologic study of cardiovascular disease in Alaska natives (GOCADAN): design and methods.

This article is a report of the design and methods of the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) Study. This longitudinal, population-based study was initiated to investigate the genetic determinants of cardiovascular disease and its risk factors. Between October 2000 and April 2004, this family study enrolled 1,214 Eskimos from several coastal villages in the Norton Sound region of Western Alaska. Examinations included a physical, laboratory determinations, and measures of subclinical disease. This study will generate a genome-wide scan for loci influencing cardiovascular disease-related traits. Relations between subclinical atherosclerosis and markers of inflammation will be examined using historic and newly drawn samples. The study will provide data on CVD prevalence, risk factors and the relative contribution of genetic and environmental determinants in Alaska Native peoples. Data from this study will contribute to the delivery of health-care and prevention of CVD in Alaska Eskimos and other populations.

Adult↗
PubMed2005

The treatment of schizophrenia: from premorbid manifestations to the first episode of psychosis.

To achieve the best therapeutic results in schizophrenia--like most other disorders--primary prevention is preferable to early and prompt treatment, which, in turn, is preferable to treatment of chronically established illness. Unfortunately, there currently exist no accurate markers that can provide information regarding the future course of illness and guide treatment in asymptomatic or mildly symptomatic individuals. Therefore, most treatment efforts are currently focused on patients who have already experienced their first psychotic episode. This paper reviews the efforts to identify accurate markers heralding psychotic illness, as well as treatment considerations in the early phase of the disease.

Early Diagnosis↗
PubMed2004

Prospective analysis of mannose-binding lectin genotypes and coronary artery disease in American Indians: the Strong Heart Study.

BACKGROUND: Mannose-binding lectin (MBL) is a circulating immune factor responsible for opsonization of pathogens and directly activating complement. Common variations in the MBL gene are responsible for an opsonic deficiency that affects 5% to 7% of whites and are associated with increased susceptibility to infections. After a preliminary report associating these variations with coronary artery disease (CAD), we determined MBL genotypes in 3 American Indian communities experiencing an increased mortality and morbidity from CAD. METHODS AND RESULTS: We examined DNA from 434 participants in a population-based cohort, the Strong Heart Study. Genotypes for 3 common MBL coding variations and 1 promoter polymorphism were determined. The frequency of a composite genotype that conferred low MBL levels was 20.7% in 217 cases and 11.1% in matched controls without CAD. A conditional logistic regression model indicated a univariate OR for CAD of 2.3 (95% CI 1.3 to 4.2, P=0.005) for the variant genotypes. After adjustment for demographic and CAD risk factors, including type 2 diabetes mellitus, fibrinogen, triglycerides, and hypertension, the OR was 3.2 (95% CI 1.5 to 7.0, P=0.004). CONCLUSIONS: Variant MBL genotypes coding for markedly diminished levels of MBL are predictive of CAD. After adjustment for multiple traditional risk factors for ischemic heart disease, this association remains significant. A high prevalence of variant MBL alleles and CAD in this population suggests that potentially important public health benefits may accrue from future interventions based on these genotypes.

Cohort Studies↗
PubMed2004

Emotional reactions of lay persons to someone with Alzheimer's disease.

BACKGROUND: Information about the nature of public reactions to people with Alzheimer's disease (AD) can help reduce stigmatization associated with the disease. OBJECTIVE: The aim of this study was to examine emotional reactions to persons with AD, and its correlates. METHODS: A total of 150 Jewish Israeli adults (mean age=59.9) were interviewed face-to-face regarding their emotional reactions to people with AD using a vignette methodology. RESULTS: Only a third of the participants gave the correct label. The person described in the vignette elicited more positive than negative emotions. Gender and perceived threat were the most important factors associated with emotional reactions. CONCLUSIONS: Findings suggest the need to expand the efforts to increase the recognition of AD by lay persons, and to address the negative emotions of several risk groups, such as male adults and those with greater concern about developing the disease.

Affect↗
PubMed2004

Efficacy and safety of long-acting risperidone in elderly patients with schizophrenia and schizoaffective disorder.

BACKGROUND: Elderly patients are often an underserved population in terms of optimizing treatment outcomes. Long-acting risperidone, the first long-acting injectable atypical antipsychotic, can improve outcomes through continuous medication delivery. OBJECTIVE: To assess the efficacy and safety of long-acting injectable risperidone in elderly patients with psychotic disorders. METHODS: This is a subanalysis of 57 patients aged > or =65 years enrolled in an open-label study of long-acting risperidone that included 725 symptomatically stable patients with schizophrenia or schizoaffective disorder. Patients were assigned to receive 25, 50, or 75 mg of long-acting risperidone every 2 weeks for up to 50 weeks. RESULTS: Fifty-seven elderly patients (mean +/- SE age, 70.9 +/- 0.7 years) were enrolled. Mean Positive and Negative Syndrome Scale (PANSS) total scores improved significantly throughout the study and at endpoint (p < 0.001). The PANSS factor scores (positive symptoms, negative symptoms, disorganized thoughts, uncontrolled hostility/excitement, and anxiety/depression) also significantly improved (p < 0.01). Clinical improvement (> or =20% reduction in PANSS total scores) was achieved by 49% of these stable patients, and 55% improved on the Clinical Global Impressions scale. Severity of movement disorders (Extrapyramidal Symptom Rating Scale scores) was reduced significantly. Adverse events reported in >10% of patients were insomnia (14%), constipation (12%), and bronchitis (12%). CONCLUSIONS: Long-acting risperidone was associated with significant symptom improvements in stable elderly patients with schizophrenia or schizoaffective disorder. Treatment was well tolerated.

Aged↗
PubMed2004

Higher rates of cigarette smoking in male adolescents before the onset of schizophrenia: a historical-prospective cohort study.

OBJECTIVE: The prevalence of cigarette smoking among schizophrenia patients is significantly higher than in the general population; this may reflect self-medication of symptoms and/or adverse effects of neuroleptics. The authors examined the prevalence of cigarette smoking in apparently healthy adolescents later hospitalized for schizophrenia. METHOD: Each year, a random sample of male Israeli military recruits, who have been screened and found not to be suffering from major psychopathology, complete a smoking questionnaire. Through the Israeli National Psychiatric Hospitalization Case Registry, 14,248 of these adolescents were followed to determine later psychiatric hospitalization. RESULTS: Of the 14,248 adolescents assessed, 4,052 (28.4%) reported smoking at least one cigarette a day. Over a 4-16-year follow-up, the prevalence of schizophrenia in the entire cohort was 0.3% (N=44). Smokers were at greater risk for later schizophrenia; the adjusted relative risk was 1.94, and the 95% confidence interval (CI) was 1.05-3.58. The number of cigarettes smoked was significantly associated with the risk for schizophrenia. Compared to nonsmokers, adolescents who smoked 1-9 cigarettes/day were 1.38 times (95% CI=0.48-4.00) as likely to be hospitalized later for schizophrenia, and adolescents who smoked 10 cigarettes/day or more were 2.28 times (95% CI=1.19-4.34) as likely; the latter difference was statistically significant. CONCLUSIONS: Taken together with the existing data on abnormalities in nicotinic transmission in patients and their relatives, this higher prevalence of smoking in future schizophrenia patients, before the onset of their illness, might indicate that impaired nicotinic neurotransmission is involved in the pathophysiology of schizophrenia.

Adolescent↗
PubMed2004

Behavioral and psychological symptoms in patients with dementia as a target for pharmacotherapy with risperidone.

OBJECTIVE: To examine the effect of risperidone on specific behavioral and psychological symptoms of dementia (BPSD). METHOD: We conducted a post hoc exploratory analysis of an integrated database from 3 randomized, controlled trials of risperidone versus placebo in treating 1150 nursing home residents with BPSD. Changes in scores were measured for items on the Cohen-Mansfield Agitation Inventory (CMAI) and Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD). RESULTS: On the CMAI, risperidone was significantly more effective in treating hitting (p = .000), hurt self or other (p = .005), cursing or verbal aggression (p = .000), repetitive sentences or questions (p = .001), scratching (p = .041), general restlessness (p = .001), grabbing onto people (p = .028), constant request for attention (p = .041), pacing and aimless wandering (p = .013), and performing repetitious mannerisms (p = .045). On the BEHAVE-AD, risperidone was significantly more effective in treating physical threats and/or violence (p = .000), verbal outbursts (p = .000), other anxieties (p = .01), agitation (p = .000), tearfulness (p = .03), and nonparanoid delusions (p = .02). CONCLUSIONS: The items from the BEHAVE-AD and CMAI that were improved with risperidone included psychotic, agitated, and aggressive symptoms. These data suggest that risperidone is more effective than placebo in treating a variety of symptoms associated with dementia.

Aged↗
PubMed2004

Body mass index and future schizophrenia in Israeli male adolescents.

BACKGROUND: Compared with the general population, individuals suffering from schizophrenia are more likely to be overweight, a finding attributed to the effect of antipsychotic medications, poor nutrition, and sedentary lifestyle. As evidence accumulates indicating that some aspects of the illness manifest before the onset of psychosis and establishment of the diagnosis, it has been suggested that increased weight, like other metabolic dysfunctions, might precede active illness. METHOD: Data on height and weight of 203,257 male adolescents assessed by the Israeli Draft Board, and followed for 2-6 years for later hospitalization for schizophrenia using the Israeli National Psychiatric Hospitalization Case Registry, were analyzed. RESULTS: From the entire cohort, 309 (0.15%) were later hospitalized for schizophrenia (ICD-10). After removing adolescents with evidence of illness before or within 1 year of the Draft Board assessment, 204 future schizophrenia patients were available for analysis. Compared with the rest of the cohort, future schizophrenia patients had lower body mass indexes (21.24 +/- 3.3 kg/m2 vs. 21.77 +/- 3.5 kg/m2; F = 4.682, df = 1, p = .03) and weighed slightly but significantly less (64.2 +/- 11.6 kg vs. 66.3 +/- 12.0 kg; F = 6.615, df = 1, p = .01). The mean height of the future patients did not differ significantly from the mean height of the remaining cohort (173.63 +/- 6.7 cm vs. 174.40 +/- 6.9 cm; F = 2.520, df = 1, p = .112). When reanalyzing the data, controlling for physical activity and socioeconomic status, the differences between the groups remained significant. CONCLUSION: Before the onset of illness, future schizophrenia patients are not heavier compared with their peers. This implies that the increased weight of patients with schizophrenia is related to illness effects, including the effects of antipsychotic medication.

Adolescent↗
PubMed2004

[Placebo-controlled trials in schizophrenia].

BACKGROUND: Clinical trials involving human subjects give rise to ethical and medico-legal dilemmas. Essential research of new drugs may potentially expose patients to ineffective medications or to placebo. The complexity of the problem increases when dealing with mentally ill patients, for whom, on the one hand there is no known cure for their disease, and on the other hand, it is sometimes questionable whether or not they are able to provide informed consent to participate in clinical trials. PURPOSE: The Israel Psychiatric Association decided to develop a position paper on the subject of placebo-controlled clinical trials in schizophrenia patients. METHODS: Discussion groups were established, and the available material in the professional literature was examined, with an emphasis on recent developments. The Declaration of Helsinki and its amendments were analyzed, and experts in the field were consulted. DISCUSSION: Clinical drug trials for development of new medications are essential in all fields of medicine, especially in psychiatry. The requirement for a placebo arm in pharmaceutical trials presents ethical and clinical dilemmas that are especially complicated with regard to mentally ill persons whose free choice and ability to provide informed consent may be questionable. However, we do not believe that this predicament justifies unconditional rejection of placebo use in psychiatry, when it may provide substantial benefit for some patients. Simultaneously, it is our duty to provide stringent restrictions that will enable strict supervision over the scientific, clinical and ethical aspects of the trials. CONCLUSIONS: We propose the following criteria for approval of pharmaceutical trials that include a placebo arm: scientific justification; clinical and ethical justification; provision of informed consent; recruitment of patients hospitalized voluntarily; prevention of harm; administration of additional potential therapeutic interventions; benefit to patients participating in the study; control and follow-up procedures for the study as determined by the local Helsinki Committee; and appointment of a supervisory mechanism by the administration of the medical institution where the study is being performed.

Clinical Trials as Topic↗
PubMed2004

Psychiatric services in nursing homes in Israel: should the American legislation be adopted?

BACKGROUND: Nursing homes provide care for the elderly who require medical, nursing or rehabilitation services. Legislation for the public health model of mental health care for nursing home residents in the USA was enacted in 1987. OBJECTIVE: To determine whether the USA act regulating psychiatric care for nursing homes may be applied in Israel. METHODS: Publications analyzing the outcome of the USA regulations demonstrate improved care as reflected by decrease in restraints and better use of psychotropic compounds. The shortcomings as well as benefits of the USA legislation are tested as to their relevance to the specific economic, environmental and medical issues in Israel. CONCLUSIONS: The adoption of USA legal acts regulating nursing home residents' psychiatric care may not be feasible in Israel. However, quality of care in nursing homes can be significantly improved if such regulations were "tailored" to Israel's unique structure of nursing homes.

Aged↗
PubMed2003

Cognitive performance in schizophrenia patients assessed before and following the first psychotic episode.

BACKGROUND: The purpose of this historical prospective study was to follow the cognitive impairment in schizophrenia from the premorbid period until shortly after the onset of the first psychotic episode within the same subjects. METHODS: Forty-four first episode schizophrenia patients were enrolled in the study. Their cognitive performance was assessed as part of the Israeli Draft Board aptitude assessments at ages 16-17, when all were found to be in good mental health (first assessment) and again, following the manifestation of the first psychotic episode (second assessment). Forty-four healthy comparisons were also enrolled and tested twice, at the same ages as the patients. Both times, the assessments included four subtests assessing abstract reasoning (Raven Progressive Matrices-R), mental speed and concentration (Otis-R), verbal reasoning (Similarities-R), and mathematical abilities (Arithmetic-R). RESULTS: A within group analysis did not reveal statistically significant changes between the first and the second assessment among the schizophrenia patients on any measure. However, a between group comparison of changes showed that relative to the healthy comparisons, schizophrenia patients deteriorated on the RPM-R (p=0.021) and Otis-R (p<0.001), but not on the Similarities-R and Arithmetic-R. Schizophrenia patients performed worse than comparisons in all four subtests on the first and second assessments (all p<0.01). CONCLUSIONS: The results indicate that most of the cognitive impairment exhibited by first-episode schizophrenia patients precedes the first psychotic episode. A decline between ages 16 and 17 and the onset of psychosis is evident in some but not all cognitive functions.

Adolescent↗