Biomedical subjects

M Gatz

Publications and source records attributed to M Gatz.

At least 19 recordsLinked to original sources

PubMed2005

Women, Co-occurring Disorders, and Violence Study: evaluation design and study population.

The Women, Co-occurring Disorders, and Violence Study (WCDVS) was a multi-site cooperative study to evaluate new service models for women with co-occurring mental health and substance use disorders and a history of physical and/or sexual abuse. Despite common features in the service interventions and evaluation procedures, diversity across the nine sites plus differences introduced by non-random assignment led to numerous methodological challenges. This article describes the design, measurement, and analysis decisions behind the WCDVS and lays the foundation for understanding participant-level outcomes and service costs. This article also describes the study population, as recruited and following attrition at the 6-month follow-up, in order to address the threat of selection bias to inferences drawn from this multi-site study.

Adult↗

PubMed2004

Gender differences in heritability of depressive symptoms in the elderly.

BACKGROUND: The present study aimed to investigate the relative importance of genetic and environmental influences on depressive symptoms in the elderly. METHOD: Depressive symptoms were assessed through the Center for Epidemiological Studies-Depression (CES-D) scale. The CES-D scale was administered to 959 twin pairs (123 female MZs, 90 male MZs, 207 same-sex female DZs, 109 same-sex male DZs and 430 opposite-sex DZs) aged 50 years or older (mean age 72 years). A dichotomous depressed state variable was constructed based on CES-D cut-offs and self-reported use of antidepressant medication. Structural equation models were fitted to the data to dissect genetic and environmental variance components. RESULTS: The sex-specific heritability estimates for depressive symptoms were 14% for males and 29% for females and 23% when constrained to be equal for men and women. The prevalence of clinically significant depressive symptoms was 16% for men and 24% for women. Heritability estimates for the dichotomous depressed state measure were 7% for males and 49% for females in the full model and 33% when constrained to be equal. CONCLUSION: Our results suggest that depressive symptoms in the elderly are moderately heritable, with a higher heritability for women than men, although differences in heritability estimates were not statistically significant.

Aged↗

PubMed2003

Association between depressed mood in the elderly and a 5-HTR2A gene variant.

The aim of this study was to investigate any possible association between depressed mood in the elderly and two candidate SNPs in the serotonin system: one in the 5-HTR2A gene promotor (-1438 G/A) and one in the 5-HT transporter gene (-925 C/A). DNA from a population-based Swedish twin sample (N = 1,592; mean age = 73) was genotyped using Pryosequencing trade mark. An association was found between the 5-HTR2A gene promotor polymorphism and depressed mood (OR: 1.5, CI: 1.1-2.1) for the A/A genotype in the total sample. When the sample was analyzed by gender, a significant association (OR: 2.4, CI: 1.4-4.4) was found for males and the A/A genotype, but not for females. The 5-HT transporter gene was not associated with depressed mood in this elderly population. These results suggest that there might be different genetic mechanisms for males and females contributing to the development of depressed mood in the elderly.

Aged↗

PubMed2001

Multiple-threshold models for genetic influences on age of onset for Alzheimer disease: findings in Swedish twins.

Twin studies of dementia have typically used relatively simple 2 x 2 contingency tables with one threshold to estimate the relative importance of genetic variance for liability to disease. These designs are inadequate for addressing issues of age at onset, censoring of data, and distinguishing shared environmental effects from age effects. Meyer and Breitner [1998: Am J Med Genet 81:92-97] applied a multiple-threshold model to the NAS-NRC Twin Panel (average age of onset, 63.5 years) and report that additive genetic effects and shared environmental effects account for 37% and 35% of the variation, respectively, in age of onset for Alzheimer disease. We apply a modified version of their model to the Study of Dementia in Swedish Twins (average age of onset, 75 years) and find that genetic effects account for 57%-78% of the variance, whereas shared environmental effects are of no importance. Heritability is lower when thresholds are freely estimated rather than fixed to the population prevalences. We interpret the findings to suggest that models with free thresholds confound influences on longevity with influences for the disease. Multiple-threshold models, however, do not confound age effects with shared environmental influences.

Age of Onset↗

PubMed2001

A longitudinal analysis of anxiety and depressive symptoms.

The authors modeled depressive and anxiety symptom data from 1,391 participants in a longitudinal study of middle-aged and older Swedish twins (M age = 60.9 years, SD = 13.3). Although anxiety and depression were highly correlated, a model with distinct Anxiety and Depression factors fit the data better than models with Positive and Negative Affect factors or a single Mental Health factor. Lack of well-being was associated with anxiety rather than depression. Over two 3-year intervals, anxiety symptoms led to depressive symptoms, but the relationship was not reciprocal. Anxiety symptoms were more stable than depression. These findings provide additional support for the idea that anxiety symptoms may reflect a personality trait such as neuroticism more than do depressive symptoms and suggest that low positive affect may not be as specific to depression among older adults as in younger people.

Adult↗

PubMed2001

Symptoms of depression in the oldest old: a longitudinal study.

This study examined depressive symptoms in a population-based, longitudinal sample of people aged 80 and older to determine initial prevalence of depressive symptoms and changes over time. Depressive symptomatology was assessed with the Center for Epidemiologic Studies-Depression scale (CES-D). The sample was drawn from the OCTO-Twin study, which examined 702 Swedish twins over age 80 in which both members of the pair were still surviving. For the present study, one member of each twin pair was randomly selected, resulting in a sample of 351. A comprehensive biobehavioral assessment was conducted at three time points over 4 years. Depressive symptoms were initially relatively low and decreased significantly between Wave 1 and Wave 2. At Wave 3, depressive symptoms increased slightly but not significantly. Participants who received a dementia diagnosis at some point in the study did not differ significantly on initial CES-D scores when compared to those participants who never received such a diagnosis. Lack of well-being, as opposed to negative affect, was the biggest contributor to the overall depression score at each of the three waves of measurement. Predictors of negative affect for this sample included activities of daily living, subjective health, and performance on the cognitive test, block design. None of these predictors were significant for lack of well-being.

Activities of Daily Living↗

PubMed2001

Education and the risk of Alzheimer's disease: findings from the study of dementia in Swedish twins.

The association between dementia and education was studied in 143 twin pairs discordant for dementia, using a matched-pair design, and in 221 dementia cases and 442 unrelated controls from the same twin registry, using a case-control design. Low education was defined as 6 years or less of schooling. Case-control analyses with prevalent cases showed low education to be a risk for Alzheimer's disease but not dementia in general. Low education did not significantly predict incident cases. In the matched-pairs analysis, which controls for genetic and other familial influences, differences in education between demented twins and twin partners were not statistically significant. However, for Alzheimer's disease, odds ratios resulting from matched pairs and case-control analyses were similar. Twins' comparative reports about intellectual involvement earlier in their lives suggest a long-standing difference on this dimension, with less involvement by the twin who became demented.

Aged↗

PubMed2001

Deficits in controlled processing may predict dementia: a twin study.

This study tested for differential patterns of cognitive decline in 33 twin pairs for which both were nondemented, but 1 member of the pair went on to develop dementia. Compared with their nondemented twin partners, twins who later developed dementia already showed poorer performance on tests of memory and attention, visuospatial-reasoning skills, and perceptual speed and the Mini-Mental State Examination (MMSE). The authors suggest that this cluster of tests reflects deficits in controlled rather than automatic cognitive processes. Nondemented twin partners of the twins who became demented were also compared with 33 matched controls selected from pairs in which both members remained nondemented. Nondemented twin partners scored lower than matched controls on tests of verbal ability, memory and attention, and perceptual speed and the MMSE. This finding indicates that nondemented twin partners of demented twins are at elevated risk themselves for becoming demented, and further suggests that certain areas of cognition are compromised prior to diagnosis of dementia.

Aged↗

PubMed2001

Age-related differences and change in positive and negative affect over 23 years.

Positive and negative affect, measured by the Bradburn Affect Balance Scale, were studied in a longitudinal sample spanning from 1971 to 1994. The sample (N = 2,804) represented 4 generations of families. Linear trend analyses compared generations over time for positive and negative affect and also examined the possible influences of neuroticism and extraversion on initial levels of affect and patterns of change in affect. Negative affect decreased with age for all generations, although the rate was attenuated among the oldest adults. Higher neuroticism scores also attenuated the decrease in negative affect across time. For positive affect, the younger and middle-aged adults showed marked stability, but the older group evidenced a small decrease over time. Higher levels of extraversion were related to more stability in positive affect.

Adolescent↗

PubMed2000

Psychosocial interventions for individuals with dementia: an integration of theory, therapy, and a clinical understanding of dementia.

We reviewed six psychosocial interventions for individuals with dementia. Interventions are described in terms of theoretical basis, how knowledge about dementia is incorporated, techniques, and empirical support. Psychodynamic approaches appear helpful for understanding intrapsychic concerns of demented individuals. Support groups and cognitive/behavioral therapy assist early stage individuals to build coping strategies and reduce distress. Reminiscence and life review provide mild to moderate stage individuals with interpersonal connections. Behavioral approaches and memory training target specific cognitive and behavioral impairments and help to optimize remaining abilities. Reality orientation reflects a similar goal, yet is probably more useful for its interpersonal functions.

Aged↗

PubMed2000

Age and emotional response to the Northridge earthquake: a longitudinal analysis.

Cross-sectional studies have found older adults to have lower levels of emotional distress after natural disasters. The maturation hypothesis suggests that older adults are less reactive to stress events, whereas the inoculation hypothesis argues that prior experience with disaster is protective. One hundred and sixty-six adults aged 30 to 102 were interviewed regarding the 1994 Northridge earthquake. Longitudinal data were available on depressed mood before and after the earthquake. The maturation hypothesis was generally not supported. The young-old were least depressed; however, this age difference was present prior to the earthquake. The old-old showed lowest levels of earthquake-specific rumination, but age did not buffer the relationship between damage exposure and rumination. The inoculation hypothesis was supported for depressed mood. Prior earthquake experience was related to lower postearthquake depression scores.

Adult↗

PubMed2000

Dexamethasone pharmacokinetics in the inner ear: comparison of route of administration and use of facilitating agents.

There is growing otologic interest in treating inner ear disorders, such as sudden sensorineural hearing loss and acute or unremitting Meniere's disease, with intratympanic dexamethasone (IT-DEX). Although anecdotally reported, there are no scientific clinical papers and few prior laboratory research publications on the subject. This study compares perilymph dexamethasone concentrations after systemic and intratympanic administration and assesses the role of 3 potential transport facilitators of IT-DEX into perilymph. Forty guinea pigs (79 ears) were randomly separated into 5 groups. Dexamethasone levels were measured by radioimmunoassay. IT-DEX resulted in higher perilymph steroid levels than intravenous dexamethasone (P < 0.05). Histamine facilitator resulted in significantly higher perilymph steroid levels than IT-DEX alone (P < 0.05). Neither hyaluronic acid nor dimethylsulfoxide was a potent facilitator. This study demonstrates that IT-DEX administration results in superior perilymph levels within 1 hour of administration and does not result in systemic absorption. Histamine is a potent facilitating agent. The clinical implications are considerable.

Administration, Topical↗

PubMed2000

Defining discordance in twin studies of risk and protective factors for late life disorders.

In studies that employ matched pair analysis to identify environmental exposures important for a disorder, criteria for discordant pairs are seldom discussed. Yet several assumptions concerning the definition of discordancy may have considerable influence over what results are found. Problems are exacerbated when age of onset for a disorder is late in life. We propose a new set of criteria for defining discordant pairs in studies of dementia, taking into account duration of discordance and competing causes of mortality, and evaluate the consequences of choosing alternative definitions of discordancy.

Age of Onset↗

PubMed1999

Application of life table analysis to the onset of dementia in a genetically informative design.

The primary objective of this study was to estimate the survival function for time to onset of dementia in initially unaffected twins from when their partner (index proband) was diagnosed with dementia of the Alzheimer's type. Survival functions generated by life table analyses were compared by zygosity and gender. Sixty-one twin pairs where at least one member had been diagnosed with dementia of Alzheimer's type were included in the analyses. Additionally, both members of the twin pair had to be alive at the time the index proband was diagnosed with dementia. The probability of remaining cognitively intact within the first three years after the proband was diagnosed was high (0.93, 95% CI 0.89, 1.0), but after 15 years the probability of remaining intact was low (0.34, 95% CI 0.16, 0.52). Age of onset of the index proband was a significant covariate in the survival functions. There were significant differences in the survival functions for monozygotic (MZ) and dizygotic (DZ) co-twins (chi2 = 3.86, 1, P < 0.05), evidencing a genetic component for age of onset for dementia, but there were no significant differences between men and women.

Age of Onset↗

PubMed1999

Genetic and behavioral risk factors for self-reported joint pain among a population-based sample of Swedish twins.

Self-reported joint pain, a typical manifestation of osteoarthritis, was examined using 335 twin pairs from the Swedish Adoption/Twin Study of Aging to estimate relative genetic and environmental influences on self-reported joint pain and to examine the relationships between joint pain, health behavior, and psychological variables. Findings suggest that family resemblance for self-reported joint pain represents similar environments more than genetic similarity. Data from the early 1970s, including exercise, physical activity at work, obesity, and neuroticism, were used to predict joint pain in 1993. For men, moderate amounts of exercise decreased the likelihood of joint pain, but strenuous amounts of physical activity in the workplace had the opposite effect. For women, exercise and physical activity were not significant predictors, but past obesity and higher levels of neuroticism increased the likelihood of reporting joint pain in 1993.

Aged↗

PubMed1999

History of depression and other psychiatric illness as risk factors for Alzheimer disease in a twin sample.

Although case-control studies have found elevated risk for Alzheimer disease (AD) associated with a prior psychiatric history, most of the previous research had inadequate controls for familial risk factors. Putative psychiatric risk factors were evaluated for a registry-based sample of 65 twin pairs discordant for AD. Risk ratios were calculated for psychiatric illness at any time and for episodes more than 10 years before dementia onset. Prior psychiatric illness was significantly associated with elevated risk. Most of these cases represented depressive episodes. When analyses were restricted to individuals whose mental illness commenced more than 10 years before dementia onset, the magnitude of the odds ratio decreased markedly. These findings suggest that a history of psychiatric illness, especially depression, may be associated with an elevated risk for AD. In particular, these results are consistent with an interpretation that symptoms of depression and similar complaints represent prodromal phases of dementia.

Aged↗

PubMed1998

[Genetic factors are often found inl Alzheimer disease. An extensive twin study to clarify the heredity-environment relationship].

Genetic and environmental risk factors are central concerns in dementia research. Through twin studies one can study the relative importance of genetic and environmental risk factors. One such study, based on the Swedish Twin Registry, shows that genetic effects are of considerable importance for developing Alzheimer's disease, even late in life, but that environmental factors are also important. For vascular dementia, the results indicate that non-genetic factors are of primary importance.

Aged↗

PubMed1998

A twin study of mortality after spousal bereavement.

BACKGROUND: Previous research has shown an increased risk of mortality after spousal bereavement, with the highest risk in the first weeks or months closest to the loss. One difficult issue in these designs is appropriate covariates and control groups. METHOD: This study is based on 1993 pairs of twins discordant for marital status and on 35860 married individuals from the Swedish Twin Registry born between 1886 and 1958 and followed for marital and vital status between 1981 and 1993. RESULTS: Spousal bereavement was a risk factor for mortality for both men and women using the still married co-twin as a control to the widowed proband, and controlling for earlier health status and health-related risk factors. The mortality risk was higher for young-old (under 70 years) individuals, and for recently widowed than for longer-term widowed. Young-old women had a pattern with increased mortality risk during the first years after bereavement, but also a markedly decreased risk if they survived 4 years after bereavement, as compared to married women. CONCLUSIONS: The results support a causal effect of bereavement on mortality. The decrease in risk for long-term young-old women is congruent with reports by widows of psychological growth after bereavement, involving increased sense of mastery and competence after learning to live in new sets of circumstances following the loss of their husband.

Adult↗