Biomedical subjects

Susan K Schultz

Publications and source records attributed to Susan K Schultz.

31 records · Page 2Linked to original sources

PubMed2002

Effects of smoking marijuana on brain perfusion and cognition.

The effects of smoking marijuana on regional cerebral blood flow (rCBF) and cognitive performance were assessed in 12 recreational users in a double-blinded, placebo-controlled study. PET with [(15)Oxygen]-labeled water ([(15)O]H(2)O) was used to measure rCBF before and after smoking of marijuana and placebo cigarettes, as subjects repeatedly performed an auditory attention task. Smoking marijuana resulted in intoxication, as assessed by a behavioral rating scale, but did not significantly alter mean behavioral performance on the attention task. Heart rate and blood pressure increased dramatically following smoking of marijuana but not placebo cigarettes. However, mean global CBF did not change significantly. Increased rCBF was observed in orbital and mesial frontal lobes, insula, temporal poles, anterior cingulate, as well as in the cerebellum. The increases in rCBF in anterior brain regions were predominantly in "paralimbic" regions and may be related to marijuana's mood-related effects. Reduced rCBF was observed in temporal lobe auditory regions, in visual cortex, and in brain regions that may be part of an attentional network (parietal lobe, frontal lobe and thalamus). These rCBF decreases may be the neural basis of perceptual and cognitive alterations that occur with acute marijuana intoxication. There was no significant rCBF change in the nucleus accumbens or other reward-related brain regions, nor in basal ganglia or hippocampus, which have a high density of cannabinoid receptors.

Adult↗

PubMed2002

The influence of cognitive impairment and psychiatric symptoms on daily functioning in nursing facilities: a longitudinal study.

The influence of psychiatric symptoms and cognitive status on daily living skills was explored among persons with dementia residing in skilled nursing facilities. Psychiatric symptoms were examined in three domains: 1) depression, 2) psychosis, and 3) behavioral disturbances. Twenty-eight subjects were followed for a 1-year duration in rural nursing facilities. The relationship between psychiatric symptoms, cognition, and daily living skills was assessed using correlation and regression analyses. Over a one-year period, cognitive and functional impairment progressed significantly. In contrast, psychiatric symptoms across all three domains did not necessarily persist or increase. Deterioration in cognitive function was significantly correlated with reduced functional status both cross-sectionally and longitudinally. Among psychiatric symptoms, only behavioral disturbances were significantly associated with functional impairment cross-sectionally. Cognitive decline and loss of social functioning may constitute the greatest source of disability among persons in nursing facilities. Furthermore, both impairments increase over time in contrast to psychiatric symptoms, which appear to have a more variable course. These findings may have implications for treatment interventions that seek to enhance functioning in the skilled nursing setting.

Activities of Daily Living↗

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

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

Global cerebral blood flow in relation to cognitive performance and reserve in subjects with mild memory deficits.

PURPOSE: This study was undertaken to explore the mechanisms underlying cognitive reserve in subjects with mild memory deficits by using positron emission tomography (PET). METHODS: Global cerebral blood flow (gCBF) and cerebrovascular reserve (CVR) measurements were performed in 15 elders (5 men, 10 women, 62-84, 71.8 +/- 6.2 years) meeting criteria for mild cognitive impairment (MCI). PET consisted of quantitative [(15)O]water determinations of CBF, two at baseline and one postadministration of acetazolamide (ACZ). RESULTS: Mean gCBF were 44.9 +/- 5.5 during counting, 44.5 +/- 6.7 for the memory task, and 60.2 +/- 4.8 ml/min/100 g for post-ACZ (CVR of 33.9 +/- 13.2%). Task-related gCBF change was significantly related to memory score, performance on the Trail Making Test B (Trails-B), premorbid IQ, and education, and differed significantly between the learning-based groups. CONCLUSIONS: Cognitive reserve appears analogous to cardiac reserve. The ability to alter gCBF paralleled performance on general cognitive measures, was enhanced in higher levels of cognitive reserve, and was impaired in individuals who no longer appear to benefit from repeated exposure to testing.

Acetazolamide↗

PubMedDate not supplied

Anxiety and impaired social function in the elderly.

The effect of anxiety on impairment in activities of daily living was examined among elderly individuals residing in a long-term care setting. Eighty one subjects received complete assessments of psychiatric symptoms, cognitive impairment, and ability to perform daily living tasks. A multivariate analysis was conducted to determine the relative influence of anxiety, cognitive status, and depressive symptoms on daily living skills. The presence of anxiety was significantly associated with reduced functional status in performing activities of daily living. This relationship remained significant even after controlling for the presence of concurrent depressive symptoms as well as cognitive impairment. Anxiety is a significant source of morbidity among elderly individuals and substantially impairs social function over and above the effects of depression and cognitive decline. Current interventions for anxiety such as benzodiazepines may have adverse cognitive effects, hence more specific intervention strategies for anxiety may be very important for this population.

Activities of Daily Living↗

PubMedDate not supplied

Basal metabolic rate in anorexia nervosa patients: using appropriate predictive equations during the refeeding process.

BACKGROUND: The refeeding process is a particularly dangerous time for some anorexia nervosa (AN) patients. Great physiologicatress can occur from imposing a large caloric intake on a body dealing with the effects of long-term starvation. Accurate predictive equations of basal metabolic rate (BMR) are needed to ensure AN patients gain weight at a safe rate. METHODS: Patients with AN undergoing strictly controlled nutritional rehabilitation on an inpatient unit were examined for changes in BMR via indirect calorimetry. Seven female patients were assessed shortly after inpatient admission. Follow-up measures of weight and BMR were obtained after three weeks of refeeding treatment comprised of approximately 3500 kcal/day. RESULTS: Body mass index (BMI) increased in all subjects from a median 13.7 kg/m2 at baseline to 15.2 kg/m2. BMR also increased from a median of 1000 kcal/day to 1220 kcal/day. The Owens and Mifflin equations were moderately accurate (within 10%) of predicted BMR at baseline and 3-week follow-up, and the Harris-Benedict equation was very accurate (within 2%) at 3-week follow-up only. CONCLUSIONS: These results may guide nutritional therapies for AN by demonstrating the suppression of metabolism induced by calorie restriction as well as its relatively prompt rebound to expected values with weight gain. Derivation of accurate predictive equations for use during the early refeeding period is needed.

Adult↗

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

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↗