Biomedical subjects

Stephan Arndt

Publications and source records attributed to Stephan Arndt.

51 records · Page 3Linked to original sources

PubMed2002

CYP2D6 polymorphisms and atypical antipsychotic weight gain.

Reports have linked atypical antipsychotics (AAPs) with weight gain. The polymorphic CYP2D6 involved in metabolism has been associated with medication morbidity. Eleven subjects receiving olanzapine were genotyped for CYP2D6 to examine the relationship between 2D6 and AAP weight gain. Using a linear regression, the dependent variable was percent change in body mass index (BMI). Genotype, dose and duration of treatment were independent. Genotype was significant (P<0.0097) for those with a *1/*3 or *4 genotype experiencing a larger percent BMI change than those with a *1/*1 genotype. This may be due to increased olanzapine concentrations leading to increased exposure, which may trigger AAP weight gain.

Adult↗

PubMed2002

Longitudinal assessment of premorbid cognitive functioning in patients with schizophrenia through examination of standardized scholastic test performance.

OBJECTIVE: Studies suggest the presence of premorbid cognitive impairment in patients with schizophrenia, yet the onset and course of these deficits remain unclear. The purpose of this study was to investigate the longitudinal course of premorbid cognitive functioning in individuals with schizophrenia by using prospective data obtained from scholastic test results. METHOD: Scores from grades 4, 8, and 11 on the Iowa Tests of Basic Skills and the Iowa Tests of Educational Development were obtained for 70 subjects who later developed schizophrenia. The mean percentile rank of the subjects' scores in the areas of vocabulary, reading comprehension, language, mathematics, sources of information, and an overall composite category were compared with state norms. RESULTS: The subjects scored below the 50th percentile for each category in all three grades, but only language, reading, sources of information, and composite scores from grade 11 were significantly below state norms. With regard to longitudinal course, there was a significant linear decrease in language scores over time. Scores from grade 11 were positively correlated with WAIS-R IQ, verbal fluency, and Rey Auditory Verbal Learning scores at first illness episode. Scores from grade 11 were not significantly correlated with age at illness onset or ratings of disorganized, psychotic, or negative symptoms. CONCLUSIONS: Scholastic test scores at grades 4 and 8 were nonsignificantly below average in this group of children who later developed schizophrenia. However, test scores dropped significantly between grades 8 and 11. This corresponds to ages 13-16 years, or the onset of puberty. Poor or declining scholastic performance may be a precursor to the cognitive impairment seen during the first episode of illness.

Adolescent↗

PubMed2002

Capacity to provide informed consent for participation in schizophrenia and HIV research.

OBJECTIVE: The degree to which people with psychiatric symptoms and cognitive dysfunction can provide informed consent to participate in research is a controversial issue. This study was designed to examine the capacity of subjects with schizophrenia and subjects with HIV to provide informed consent for research participation and to determine the relationships among cognitive dysfunction, psychiatric symptoms, and decisional capacity. METHOD: Twenty-five men and women with a DSM-IV diagnosis of schizophrenia and 25 men and women with HIV were recruited. The groups were compared in terms of neuropsychological functioning, psychiatric symptoms, and ability to provide informed consent to a hypothetical drug trial. RESULTS: Eighty percent of the subjects with schizophrenia and 96% of the HIV-positive subjects demonstrated adequate capacity to consent to the hypothetical drug trial, but subjects in the schizophrenia group had significantly lower scores on two of the four aspects of decisional capacity. For the subjects with schizophrenia, neuropsychological functioning and psychiatric symptoms (e.g., apathy and avolition), but not psychotic symptoms (e.g., hallucinations and delusions), were significantly associated with decisional capacity. CONCLUSIONS: The majority of subjects who are recruited and willing to participate in schizophrenia or HIV research will have adequate capacity to provide consent. Cognitive dysfunction and the symptoms shown to be associated with impaired decisional capacity are not unique to schizophrenia and may occur with many other forms of illness. These findings underscore the importance of considering how decisional capacity will be assessed in all types of research, regardless of the specific condition being studied.

Adolescent↗

PubMed2002

Age and regional cerebral blood flow in schizophrenia: age effects in anterior cingulate, frontal, and parietal cortex.

Positron emission tomography ([(15)O] water PET) was used to examine the relationship between age and regional cerebral blood flow (rCBF) in schizophrenia. Forty-nine unmedicated male patients, ages 20-51, underwent imaging during an eyes-closed resting condition. Negative correlations were observed between age and rCBF in the anterior cingulate, as well as in frontal (Brodmann area 8) and parietal cortex (area 40) bilaterally. The observation of reduced rCBF in the anterior cingulate with increased age is consistent with previous findings in healthy subjects. In contrast, the reduced flow observed in the frontal and parietal regions may be unique to schizophrenia.

Adult↗

PubMed2002

Comparison of risperidone with olanzapine in elderly patients with dementia and psychosis.

STUDY OBJECTIVES: To compare the effects of risperidone and olanzapine on cognition in elderly patients with dementia and psychosis, and to compare the side effects of these drugs. DESIGN: Single-blind, multicenter, observational study. SETTING: Four rural nursing care facilities. PATIENTS: Nineteen elderly patients with dementia and psychosis. INTERVENTION: Eleven patients were treated with risperidone, eight with olanzapine. MEASUREMENTS AND MAIN RESULTS: Rating assessments were completed at baseline, 1 month, and 2 months. Simple paired and unpaired t tests determined between- and within-group differences. Social functioning, including activities of daily living, improved over baseline in both groups (p=0.03). Cognition declined significantly (p<0.05) in the risperidone group; comparatively more side effects occurred and blood pressure decreased (p<0.05) in the olanzapine group. When compared with each group cross-sectionally at baseline and end point, however, the two groups did not differ significantly. CONCLUSION: Improvements in social functioning in all 19 patients suggest that both risperidone and olanzapine may help improve functioning in elderly patients with dementia and psychosis. Cognitive and side effect profiles of these drugs may differ substantially. Further study is needed to determine patient subpopulations who may be able to tolerate one drug over another.

Aged↗

PubMed2002

Abnormal movements and tardive dyskinesia in smokers and nonsmokers with schizophrenia genotyped for cytochrome P450 2D6.

STUDY OBJECTIVE: To investigate the relationships between cytochrome P450 (CYP) 2D6 genotype, antipsychotic drug exposure, abnormal movements and tardive dyskinesia, and cigarette smoking. DESIGN: Prospective, longitudinal study. SETTING: University mental health research center. PATIENTS: Thirty-seven patients with schizophrenia. INTERVENTION: Patients were genotyped for CYP2D6*1, *3, and *4 alleles, and data were collected on their psychiatric symptoms, cigarette smoking status, and antipsychotic drug exposure. Abnormal movements were measured using the Abnormal Involuntary Movement Scale (AIMS). Presence of tardive dyskinesia was also evaluated. MEASUREMENTS AND MAIN RESULTS: A linear regression model used the AIMS scores as the dependent variable, and genotype, sex, smoking status, and antipsychotic drug exposure as independent variables. Antipsychotic drug exposure, genotype, and cigarette smoking interaction was significant (p<0.0212) for patients with the CYP2D6*1/*3, *4 genotype. Seventy-eight percent of smokers with the CYP2D6*1/*3, *4 genotype had tardive dyskinesia compared with 20-33% of patients in other groups. CONCLUSION: Patients with a CYP2D6*3 or *4 allele may shunt antipsychotic metabolism through other pathways that are induced by cigarette smoke. This induction may result in formation of neurotoxic metabolites, leading to increased AIMS scores and a higher frequency of tardive dyskinesia compared with patients without these alleles.

Adult↗

PubMed2002

Screening for alcoholism in the primary care setting: are we talking to the right people?

BACKGROUND: This study assessed which demographic groups were most likely to consume alcohol excessively, and which groups had received inquiries and discussion about alcohol use from their physicians compared with discussions about other health risks. STUDY DESIGN: This was a cross-sectional study using data from the Centers for Disease Control Behavioral Risk Factors Surveillance System 1997 data set that represents a stratified random sample in the United States. POPULATION: We selected 23,349 adults who reported a routine physical examination within the last 3 years. OUTCOMES MEASURED: The main variables involved responses to questions about alcohol intake and whether the respondent's physician had initiated discussions about drinking. RESULTS: Physicians spoke to patients about alcohol use much less frequently than about other health-related behaviors. Discussions were roughly targeted to groups with the largest intake. However, physicians were least likely to speak with white patients, women, and widows who drank significantly. CONCLUSIONS: Regularly asking patients about alcohol use could substantially reduce the under-recognition of alcoholism. Since brief counseling is effective, negative consequences of excessive alcohol intake may be avoided.

Adult↗

PubMedDate not supplied

Coercion and informed consent in research involving prisoners.

Prison-based research has been limited due to concern that prisoners may represent a vulnerable population secondary to possible coercion and limited capacity for voluntary informed consent. This study was designed to assess decisional capacity and susceptibility to coercion in prison research subjects. Subjects were 30 mentally ill prisoners and 30 healthy controls. The groups were compared on ability to provide informed consent to a hypothetical drug trial, susceptibility to possible coercion, neuropsychological functioning, and psychiatric symptoms. Results indicated that all controls and all but one of the prisoners demonstrated adequate capacity to consent to the hypothetical drug trial. However, when decisional capacity was measured quantitatively, prisoners performed significantly worse regarding two aspects of this ability. Regarding possible coercion, prisoners' main reasons for participating in research included avoiding boredom, meeting someone new, appearing cooperative in hopes of being treated better, and helping society. Neuropsychological functioning was strongly positively correlated with decisional capacity and negatively correlated with susceptibility to possible coercion, whereas psychiatric symptoms were only weakly correlated with these variables. In conclusion, a very high percentage of particularly vulnerable, mentally ill prisoners demonstrated adequate capacity to consent to research. Lower scores on a quantitative measure of decisional capacity suggest that extra care should be taken during the consent process when working with these subjects. The reasons prisoners gave for participating in our research indicated that the prison setting may have influenced their decision to participate, but that they were not actually coerced into doing so. Despite serious past incidents, ethicists will need to consider the possibility that prisoners have become an overprotected population.

Adult↗

PubMedDate not supplied

Insomnia as a predictor for symptom worsening following antipsychotic withdrawal in schizophrenia.

Sleep disturbances have been associated with schizophrenia, and are an especially prominent feature during the prodrome preceding psychotic relapse. In this study, we examined the changes in sleep quality following withdrawal of antipsychotic treatment, as well as the predictive value of sleep disturbances on symptom exacerbation. One hundred twenty-two patients with schizophrenia, schizophreniform disorder, or schizoaffective disorder underwent a 3-week medication wash-out prior to neuroimaging studies. Sleep quality was rated using items on the Hamilton Rating Scale for Depression (HAM-D), while symptom severity was measured using the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS). Sleep quality deteriorated progressively following antipsychotic discontinuation. Total insomnia score prior to antipsychotic withdrawal had a significant effect on the severity of psychotic symptoms at the last weekly assessment, while baseline terminal insomnia had a significant effect on disorganized symptoms at the end of the medication-free period. These findings were independent of baseline symptom severity. Our findings suggest that schizophrenia patients with sleep disturbances are at a greater risk for worsening of positive symptoms after antipsychotic discontinuation. The implications of these findings in research and clinical settings are discussed.

Adult↗

PubMedDate not supplied

Drug and alcohol treatment services effective for methamphetamine abuse.

BACKGROUND: Methamphetamine abuse has become a major public health problem as demonstrated by increases in the number of emergency room visits, substance abuse treatment episodes, and arrests attributable to methamphetamine manufacture and abuse. We examine the effectiveness of conventional substance abuse treatment in the recovery of individuals seeking voluntary treatment for methamphetamine abuse. METHODS: At the request of the Iowa Department of Public Health, the Iowa Consortium for Substance Abuse Research and Evaluation contacted clients who had been admitted to voluntary treatment for methamphetamine abuse. Staff from the Consortium asked subjects to volunteer for follow-up interviews at designated intervals following admission. Agency staff conducted interviews based on the Mini International Neuropsychiatric Interview (MINI) at admission and at designated intervals and reported results to the Consortium for analysis. RESULTS: Subjects were predominantly Caucasian and over one half were female with an average age of 30 years. The criminal justice system was a primary referral source. Reported psychiatric symptoms dropped substantially in the first 60 days following admission and appeared to remain low at 6 and 12 months. Most clients reported abstinence and employment and denied arrests at the 6-month interview. Outcomes were not correlated with psychiatric symptoms. CONCLUSIONS: Psychiatric symptoms improved over time with usual substance abuse treatment. There was no evidence that referral by the court system or symptoms of antisocial personality disorder affected outcome. Conventional treatment resulted in sobriety, employment, and fewer arrests at 6 and 12 months following treatment.

Adult↗

PubMedDate not supplied

Secondary prevention of schizophrenia: utility of standardized scholastic tests in early identification.

BACKGROUND: Given the enormous societal burden of schizophrenia, there has been a growing interest in its prevention during the past decade. Early detection and prompt treatment may improve outcome in schizophrenia. In this study, we examine the value of using pre-morbid cognitive impairment in early detection. METHODS: Standardized achievement tests Iowa Test of Basic Skills (ITBS) and Iowa Tests of Educational Development (ITED) at Grades 4, 8 and 11 were examined in 70 patients with schizophrenia and 147 comparison subjects without schizophrenia. The majority of comparison subjects later developed another major mental illness such as substance abuse or mood disorder. Receiver operating characteristic curves were used to test the efficiency and accuracy of pre-morbid cognitive tests for differentiating adolescents who will later develop schizophrenia from those who remain well or develop another mental illness. RESULTS: Although schizophrenia patients had lower mean percentile ranks than comparison subjects in every ITBS/ITED sub-test, these differences were only associated with small increases in risk for schizophrenia. Standardized scholastic tests achieved moderate sensitivity and specificity, and enhanced the detection of schizophrenia by three to five fold. However, positive predictive values were low. ITBS/ITED scores alone cannot be used in screening the general population, given the low positive predictive values. CONCLUSION: Combining ITBS/ITED scores with other risk factors, such as family history, may lead to more efficient early detection. Our findings illustrate the challenges facing the secondary prevention of schizophrenia. Priority should be given to developing efficient and accurate methods of early detection in order to reduce the dangers of making erroneous false positive diagnoses, and to decrease exposure to unnecessary treatment during the testing of early interventions.

Achievement↗

PubMedDate not supplied

Adult outcomes of attention deficit hyperactivity disorder and conduct disorder: are the risks independent or additive?

METHODS: Data were obtained from a longitudinal study sample of 754 adoptees and categorized based on review of the available adoption agency, medical, and psychiatric records of the biological parents. Categorical data were analyzed using chi2 or Fisher's exact tests, as appropriate. Logistic regression analyses were used to assess the relative contribution of variables. RESULTS: There was not a statistically significant difference in the frequency or type of self-reported adult disruptive behavior, arrests, jail stays, felony arrests, or frequency of conduct disorder (CD) when inattentiveness, impulsivity, and hyperactivity were analyzed individually. The contributions of attention deficit hyperactivity disorder (ADHD) were independent and no additional increased risk for future illegal behavior was conferred by the combination of the disorders. While the effect of CD on illegal behavior was correlated with substance abuse and dependence, ADHD continued to be a significant contributor after controlling for substance abuse and dependence. CONCLUSIONS: Data indicated that ADHD and CD are related but different disorders conferring risk for adult illegal behavior or arrest. In this sample, inattention was the most common domain impaired among those with ADHD, followed closely by hyperactivity, with impulsivity reported least often among those endorsing symptoms of ADHD.

Adolescent↗

PubMedDate not supplied

Biomarkers in psychiatry: methodological issues.

Particularly in psychiatry, biological measures are increasingly sought to detect exposure to toxic agents, to assist in early identification of illness, and to enhance diagnostic certainty, provide prognostic information, and permit the mapping of outcome in a variety of disorders. The authors explore the fundamental criteria necessary to designate a biological measure as a "biomarker" and discuss the potential applications, limitations, and hazards of such markers. Authors discuss methods for establishing the validity of a biomarker. Finally, they convey a word of caution about overinterpreting the clinical or scientific value of any biological measure.

Biomarkers↗

PubMedDate not supplied

Older offenders, substance abuse, and treatment.

OBJECTIVE: The adoption of more stringent truth-in-sentencing laws and the aging of the United States population in general has led to an increase in the proportion of prison inmates age 55 years and older. Recent judicial rulings require prisoners to receive adequate medical and mental health care. Care for substance abuse is often included to reduce recidivism. However, little systematic research has been conducted on the mental health and substance abuse treatment needs of older prisoners. METHODS: The authors examined age differences in substance abuse history provided by 10,952 offenders as part of their orientation and evaluation on entry into prison. Trained substance abuse counselors interviewed each offender and recorded data in an institutional database. RESULTS: Seventy-one percent of older inmates reported a substance abuse problem. When compared with younger inmates, older offenders were more likely to abuse alcohol only. Those older inmates with abuse problems had used substances for over 40 years, yet more than one-third had never received treatment. CONCLUSION: Like younger inmates, most older offenders would benefit from substance abuse treatment. The treatment may need to be tailored to age and lack of previous treatment experience and should be sensitive to this high-risk group's additional medical needs.

Adolescent↗

PubMedDate not supplied

Alcohol use among older persons in a rural state.

OBJECTIVE: Older individuals are vulnerable to adverse consequences from alcoholism; unfortunately, alcohol-related problems are often under-identified in this group. METHODS: We characterized the demographic features of alcohol use among older adults (over age 65) in a statewide community survey. RESULTS: Approximately 15% were at risk for alcoholism. As a group, the at-risk individuals were younger than the remaining sample. Twenty percent indicated that they had previously tried unsuccessfully to stop drinking, but only 10% had received any type of treatment. CONCLUSION: This low rate of treatment intervention implies a need for enhanced recognition of alcoholism among older adults in rural settings.

Aged↗