Biomedical subjects

M Gatz

Publications and source records attributed to M Gatz.

At least 37 records · Page 2Linked to original sources

PubMed1998

Childhood adoption: long-term effects in adulthood.

Clinicians and researchers have characterized early life experiences as permanent and stable influences on the personality and subsequent life experiences of an individual. Recent conceptualizations have suggested that personal and environmental factors influencing development are not deterministic. Multiple pathways into adulthood are possible. Adoption is one potential early life stressor that may illustrate the usefulness of such conceptualizations for assessing long-term effects in adulthood. Previous studies of adoption have characterized the effects of adoption into adolescence and young adulthood. The purpose of this study was to provide an initial assessment of the long-term impact of adoption. The participants were taken from the Swedish Adoption/Twin Study of Aging. From the original sample, we identified a subsample of 60 pairs of twins who were separated and reared apart, with one member being raised by a biological parent or parents and the other by an adoptive parent or parents with no biological relationship. A series of univariate and multivariate analyses were undertaken to assess the elements associated with being reared in either an adoptive home or the home of biological parent(s). The results suggest few significant effects of adoption on the adult adjustment of adoptees. In particular, the results reflect the important mediating role of childhood socioeconomic status, suggesting that the stress of adoption itself is mediated by the type of rearing environment provided by the adoption process.

Adaptation, Psychological↗

PubMed1998

Dementia and occupational exposure to magnetic fields.

OBJECTIVES: The purpose of the present report was to assess whether occupational magnetic field exposure is a risk factor for dementia, in particular for Alzheimer's disease. METHODS: Case-control analyses were applied to 77 dementia cases, 55 of whom had Alzheimer's disease, ascertained from the population-based Swedish twin register. Two reference groups were derived, with 228 and 238 persons, respectively. Occupations were linked to a job-exposure matrix based on magnetic field measurements. Primary occupation, last occupation before reference date, and the occupation with the highest magnetic field exposure during the subject's lifetime were evaluated. RESULTS: For primary occupation, all relative risk estimates were close to unity. For last occupation, at the exposure level > or = 0.2 microT, a relative risk was found for dementia estimated at 3.3 [95% confidence interval (95% CI) 1.3-8.6] and 3.8 (95% CI 1.4-10.2) for reference groups 1 and 2, respectively. The relative risk for Alzheimer's disease was estimated at 2.4 (95% CI 0.8-6.9) and 2.7 (95% CI 0.9-7.8), respectively. For the occupation with the highest magnetic field exposure, the relative risk estimates were close to unity for reference group 1 and slightly elevated for reference group 2. The relative risk estimates were greater for the subjects who were younger at onset (< or =75 years). CONCLUSIONS: These results only partially support previous findings, but they indicate that occupational magnetic field exposure may possibly influence the development of dementia.

Aged↗

PubMed1997

Heritability for Alzheimer's disease: the study of dementia in Swedish twins.

BACKGROUND: Alzheimer's disease has been thought to have familial and sporadic forms, and several genetic defects have been identified that chiefly explain early-onset familial cases. In this study, our purpose was to detect all cases of dementia in an established twin registry and to estimate total extent of genetic contribution to liability to Alzheimer's disease. METHODS: At the first stage, members of the registry were screened for dementia, using in-person or telephone mental status testing. At the second stage, those who screened positively and their partners were referred for clinical work-ups, including neuropsychological assessment, physician examination, laboratory tests, and neuroimaging. Clinical diagnoses were assigned at a multidisciplinary consensus conference. Probandwise concordance rates were examined by zygosity, and structural modeling was applied to the data to estimate genetic and environmental influences, using both single- and multiple-threshold models. RESULTS: Sixty-five pairs were identified in which one or both was demented. The probandwise concordance rate for Alzheimer's disease among monozygotic pairs was 67%; the corresponding figure for dizygotic pairs was 22%. Heritability of liability to Alzheimer's disease was estimated to be .74; to any dementia, .43. The other variance is attributable to environmental influences. CONCLUSIONS: Findings indicate a substantial genetic effect for these predominantly late-onset Alzheimer's disease cases. At the same time, structural modeling results and large intra-pair differences in age of onset suggest that environmental factors are also important in determining whether and when an individual may develop dementia.

Age of Onset↗

PubMed1997

Age differences in information-seeking among cancer patients.

Studies examining patient populations have found that information-seeking decreases with age. However, researchers usually define information-seeking as involving only the medical establishment, while they neglect other sources of information. The present study examined the use of two types of information sources, non-medical establishment (newspaper, television, and friends) and medical establishment (doctors and nurses), among seventy-five cancer patients aged eighteen to eighty-one years. Patients responded to questionnaires asking about information-seeking, desire for more cancer information, self-perception of their knowledge about cancer, and actual knowledge of facts about cancer. For the medical establishment source, information-seeking decreased with age; however, no age differences existed for seeking non-medical establishment information. In individuals with high levels of desire for information, older adults reported more information-seeking from non-medical sources than did younger adults.

Adolescent↗

PubMed1996

Brief cognitive screening in a field survey of the oldest old.

A nationally representative survey of living conditions among persons aged 77 to 98 years included a short instrument for cognitive impairment consisting of items from the Mini-Mental State Examination (MMSE). Because of the wide range of social, health, and economic domains included in the survey, it was necessary that the instrument could be administered in a short time by interviewers without experience in neuropsychological testing. Because of the age of the subjects, the instrument must be relatively independent of sensory or motor disabilities, and be acceptable to both interviewers and older adults. There were very few problems with the use of the instrument and very little missing data. A cut-off point for cognitive impairment was ascertained for the items included in this instrument using other data sets where diagnostic confirmation was available. Being able to identify subjects who are probably cognitively impaired is helpful in a multipurpose survey study of the oldest old, both in documenting the cognitive status of the sample and in evaluating the quality of other information being collected in the study.

Age Distribution↗

PubMed1996

Factors influencing life-sustaining treatment decisions in a community sample of families.

A survey of an intergenerational community sample was undertaken to examine the importance attributed to 9 factors when considering a hypothetical life-sustaining treatment decision for oneself or for a parent. The sample consisted of 1,205 respondents ranging in age from 24 to 93. On average, factors rated as most important were mental capacity and pain, and factors rated as least important were burden of care on the family, financial strain, and the individual's age. However, the oldest generation tended to rate the latter three factors as more important to consider than did the youngest generation. There was not significant correspondence between adult children's ratings regarding a decision for a parent and their own parents' ratings regarding decisions for themselves.

Adult↗

PubMed1996

Sources of covariation among Mini-Mental State Examination scores, education, and cognitive abilities.

An adoption/twin design was used to address issues concerning the relationship between education and Mini-Mental State Examination (MMSE) performance. Data on general cognitive abilities, education, and MMSE from 110 identical twin pairs and 177 fraternal pairs aged 50 through 88 were analyzed using multivariate quantitative genetic methods. Genetic influences account for 32% and 19% of the variation in MMSE for men and women, respectively. Furthermore, all of the genetic variation in MMSE is in common with genetic variation for cognitive abilities and education. Finally, correlations between education and MMSE (.21 and .16 for men and women, respectively), which were reduced to near zero when cognitive abilities were partialed out, are primarily attributable to genetic effects for cognitive abilities. These results support the hypothesis that the association between education and MMSE performance predominantly reflects genetically mediated cerebral capacity rather than test bias or health-endangering life styles in less educated individuals.

Cognition↗

PubMed1996

A co-twin--control study of response to widowhood.

The effects of long-term and recent conjugal bereavement were investigated in a sample of 2,104 Swedish twins followed between 1984 and 1993. In co-twin-control analyses, the bereaved twin experienced significantly more depressive symptoms, more loneliness, and less life satisfaction than the married co-twin. This association existed for recently widowed (< 3 years) of both sexes. Long-term widowed (> 5 years) reported more loneliness than married individuals, and for women there was also a difference in life satisfaction. There were no effects of bereavement on perceived physical health. Individual analyses, which included all respondents regardless of the co-twin's bereavement status, showed the same pattern of results. There was also evidence for an anticipation effect of widowhood indicated by elevated depressive symptoms prior to the spouse's death. Finally, longitudinal analyses showed that it is more stressful to be bereaved when young-old than old-old, but revealed no age differences in adaptation.

Age Factors↗

PubMed1996

Children's methods of coping with stress: a twin study of genetic and environmental influences.

The relative importance of environmental and hereditary factors in how children cope with stress was examined. Emotion-focused, problem-focused, and additional coping variables were assessed in 44 monozygotic (MZ) and 30 dizygotic (DZ) twin pairs, aged 9-16 years. The effects of heritability, shared environment, and unshared environment were examined in structural modelling analyses. Genetic factors accounted for a majority of the reliable variance in four of seven coping variables, while effects of twins' shared environment were negligible for all but one coping variable. Environmental factors important to individual differences in coping strategies were primarily unique to each child (unshared between the twins), highlighting the importance of individual experiences in shaping coping behaviors.

Adaptation, Psychological↗

PubMed1995

An empirical test of telephone screening to identify potential dementia cases.

Thirty-seven subjects, 15 with a clinical diagnosis of Alzheimer's disease and 22 normal controls, participated in a study of the accuracy of telephone screening in identifying potential dementia cases. The telephone protocol and scoring algorithm resulted in 100% sensitivity and 91% specificity. The findings suggest that a brief telephone interview can serve as an efficient screening device to locate dementia cases in the context of a large-scale community-based investigation.

Aged↗

PubMed1995

Apolipoprotein epsilon 4 allele in Swedish twins and siblings with Alzheimer disease.

Allelic frequencies of apolipoprotein epsilon 4 were compared in 13 dizygotic twin pairs and 13 sibling pairs in which at least one member has Alzheimer disease (AD). Among discordant pairs of twins and siblings, frequencies were significantly greater in affected than intact partners. There was no significant difference in allelic frequencies between twins with a positive family history and twins with a negative family history. The epsilon 4 allele was more common in the sibling sample selected for family aggregation of AD than the twin sample. Several lines of evidence indicate that while the epsilon 4 allele appears to be one risk factor for AD, other etiological factors must be considered as well.

Aged↗

PubMed1994

Dementia: not just a search for the gene.

We extend the reasoning commonly applied to the understanding of chronic diseases and their prevention to Alzheimer's disease and other dementing disorders. The highly visible progress in finding genetic bases of Alzheimer's disease may leave a large proportion of cases unexplained. Rather, both genetic susceptibility and environmental factors are demonstrably important for disease expression. Thus, the research and health policy implication would be to target resources toward identifying and modifying environmental risk factors that might delay or prevent dementia.

Aged↗

PubMed1993

A cross-national self-report measure of depressive symptomatology.

The Center for Epidemiological Studies Depression scale (CES-D) was administered in Swedish to two representative samples, one aged 84 to 90 (mean = 87), the second aged 29 to 95 (mean = 61). There were both linear and quadratic differences with age: the oldest individuals were highest on depressive symptoms, but younger adults were higher than middle-aged. Dimensions or subscales identified by previous studies were generally replicated, including a sadness and depressed mood factor, a psychomotor retardation and loss of energy factor, and a well-being factor (on which items are reverse-scored to indicate depression). The findings support cross-national use of the CES-D to assess self-reported symptoms of depression in adults and older adults.

Adult↗

PubMed1993

Use of twin cohorts for research in Alzheimer's disease.

The causes of Alzheimer's disease (AD) remain a mystery despite the recent identification of several putative environmental risk factors and the discovery of several linked genetic loci and point mutations associated with the disease. Particularly uncertain is the generalizability of the genetic findings to the common forms of disease encountered in clinical practice or population research. Twin studies of AD can illuminate causal mechanisms, both genetic and environmental. This consensus document explores the rationale for such twin studies, as well as a number of methodologic problems that render them difficult to implement or interpret. We review existing twin studies of AD and note several ambitious new studies. Finally, we delineate several practical strategies for the near future of twin research in AD.

Aged↗

PubMed1993

Cross-generational attributions concerning locus of control beliefs.

Age differences and attributions of age differences in locus of control orientation were examined for college students and older adults. Self-ratings and ratings of the other group by sixty college students and ninety-seven older adults were measured using Rotter's locus of control items in a Likert format. Findings showed that both age groups misattributed levels of control orientation to the other group when compared to that group's self-ratings. Older adults endorsed more internal beliefs than did college students. College students viewed older adults as more external than older adults viewed themselves, while older adults viewed college students as more internal than students' self-ratings indicated. The common perception in gerontological literature that older adults are particularly external in their locus of control beliefs may represent an erroneous attribution rather than self-reported beliefs.

Adult↗

PubMed1992

The mental health system and older adults in the 1990s.

Trends in mental health services for older adults during the past decade were used to predict salient issues for the current decade. These include overreliance on inpatient treatment, increased use of general hospitals as treatment sites, inadequate integration with the nursing-home industry, and insufficient mental health referrals from general medical providers. In the decade ahead, the mental health needs of older adults are unlikely to be an identified focus; rather the issues will overlap with other priorities (e.g., biomedical research on brain functioning, alternative treatment programs for the chronically mentally ill, and containing health care costs). Advocates for the elderly will be successful to the extent that they cast aging services within the context of these other concerns.

Aged↗

PubMed1992

Importance of shared genes and shared environments for symptoms of depression in older adults.

The Center for Epidemiologic Studies-Depression scale was administered to 68 identical and 161 fraternal twin pairs reared apart and 114 identical and 138 fraternal pairs reared together to ascertain relative genetic and environmental contributions to individual differences in self-reported depressive symptoms. Intraclass correlations and model fitting indicated that genetic influences explained 16% of the variance in total depression scores and 19% for the Psychomotor Retardation and Somatic Complaints subscale, but heritability was minimal for the Depressed Mood and Well-Being subscales. Influence of family rearing context played a substantial role in explaining twin similarity, whereas unique life experiences accounted for the greatest proportion of variance. Significant age group differences were observed, with heritability greater in twins of 60 years of age or older than in twins under 60, especially for Psychomotor Retardation.

Adoption↗

PubMed1992

Salient life events in three-generation families.

A short, simple procedure for eliciting salient life events is reported in this article. Respondents from three-generation families were asked to list events that had had an impact on them and their families. Responses were examined for content, criterion, and construct validity. The 10 events listed by 10% of at least one generation were major life cycle markers: Six (marriage, childbirth, divorce, retirement, widowhood, and ill health) pertained to the individuals, and four (marriage, birth, divorce, and ill health) pertained to their extended family networks. The expected relationship between events and depression (CES-D) was observed: The importance of low frequency events was reflected in their relationship to depression in the middle-aged and youngest generations. The importance of network events was reflected both in their presence on the lists of all age groups, and in their relationship to depression in the youngest generation.

Adult↗