Margaret Gatz

Depression in older adults

Depression is less prevalent among older adults than among younger adults, but it can have serious consequences. More than half of cases represent a first onset in later life. Although suicide rates in the elderly are declining, they are still higher than in younger adults and are more closely associated with depression. Depressed older adults are less likely to endorse affective symptoms and more likely to display cognitive changes, somatic symptoms, and loss of interest than are depressed younger adults. Risk factors leading to the development of late-life depression likely comprise complex interactions among genetic vulnerabilities, cognitive diathesis, age-associated neurobiological changes, and stressful events. Insomnia is an often overlooked risk factor for late-life depression. We suggest that a common pathway to depression in older adults, regardless of which predisposing risks are most prominent, may be curtailment of daily activities. Accompanying self-critical thinking may exacerbate and maintain a depressed state. Offsetting the increasing prevalence of certain risk factors in late life are age-related increases in psychological resilience. Other protective factors include higher education and socioeconomic status, engagement in valued activities, and religious or spiritual involvement. Treatments including behavioral therapy, cognitive-behavioral therapy, cognitive bibliotherapy, problem-solving therapy, brief psychodynamic therapy, and life review/reminiscence therapy are effective but are too infrequently used with older adults. Preventive interventions including education for individuals with chronic illness, behavioral activation, cognitive restructuring, problem-solving skills training, group support, and life review have also received support.

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.

The Swedish Twin Registry in the Third Millennium: An Update

The Swedish Twin Registry was first established in the late 1950s. Today it includes more than 170,000 twins--in principle, all twins born in Sweden since 1886. In this article we describe some ongoing and recently completed projects based on the registry. In particular, we describe recent efforts to screen all twins born between 1959 and 1985, and young twin pairs when they turn 9 and 12 years of age. For these studies, we present initial frequencies of common conditions and exposures.

The sources of co-morbidity between major depression and generalized anxiety disorder in a Swedish national twin sample.

BACKGROUND Prior studies report high levels of co-morbidity between major depression (MD) and generalized anxiety disorder (GAD) and suggest that these disorders are closely related genetically. The personality trait of neuroticism (N) is substantially correlated with risk for MD and GAD. METHOD Bivariate twin models were applied to lifetime diagnoses of modified DSM-IV diagnosis of MD and GAD obtained at personal interview in 1998-2003 with 37296 twins from the population-based Swedish Twin Registry. A trivariate Cholesky model with N, MD and GAD was applied to a subset (23280 members of same-sex twin pairs) who completed a self-report questionnaire assessing N in 1972-1973. RESULTS In the best-fit bivariate model, the genetic correlation between MD and GAD was estimated at +1.00 in females and +0.74 in males. Individual-specific environmental factors were also shared between the two disorders with an estimated correlation of +0.59 in males and +0.36 in females. In the best-fit trivariate Cholesky model, genetic factors indexed by N impacted equally on risk for MD and GAD in males and females. However, in both sexes, genetic risk factors indexed by N contributed only around 25% to the genetic correlation between MD and GAD. CONCLUSION Genetic risk factors for lifetime MD and GAD are strongly correlated, with higher correlations in women than in men. Although genetic risk factors indexed by the personality trait of N contribute substantially to risk for both MD and GAD, the majority of genetic covariance between the two disorders results from factors not shared with N.

Midlife overweight and obesity increase late-life dementia risk A population-based twin study

Objective: The relation of overweight to dementia is controversial. We aimed to examine the association of midlife overweight and obesity with dementia, Alzheimer disease (AD), and vascular dementia (VaD) in late life, and to verify the hypothesis that genetic and early-life environmental factors contribute to the observed association. Methods: From the Swedish Twin Registry, 8,534 twin individuals aged ≥65 (mean age 74.4) were assessed to detect dementia cases (DSM-IV criteria). Height and weight at midlife (mean age 43.4) were available in the Registry. Data were analyzed as follows: 1) unmatched case-control analysis for all twins using generalized estimating equation (GEE) models and 2) cotwin matched case-control approach for dementia-discordant twin pairs by conditional logistic regression taking into account lifespan vascular disorders and diabetes. Results: Among all participants, dementia was diagnosed in 350 subjects, and 114 persons had questionable dementia. Overweight (body mass index [BMI] >25–30) and obesity (BMI >30) at midlife were present in 2,541 (29.8%) individuals. In fully adjusted GEE models, compared with normal BMI (20–25), overweight and obesity at midlife were related to dementia with odds ratios (ORs) (95% CIs) of 1.71 (1.30–2.25) and 3.88 (2.12–7.11), respectively. Conditional logistic regression analysis in 137 dementia-discordant twin pairs led to an attenuated midlife BMI-dementia association. The difference in ORs from the GEE and the matched case-control analysis was statistically significant (p = 0.019). Conclusions: Both overweight and obesity at midlife independently increase the risk of dementia, AD, and VaD. Genetic and early-life environmental factors may contribute to the midlife high adiposity–dementia association.

Life Review Therapy Using Autobiographical Retrieval Practice for Older Adults With Depressive Symptomatology.

The aim of this study was to examine the efficacy of life review based on autobiographical retrieval practice for treating depressed older adults. Forty-three adults aged 65-93 with clinically significant depressive symptomatology and no dementia were randomly assigned to treatment or to no treatment. The results indicated significant differences between experimental and control groups after 4 weeks of autobiographical retrieval practice. At posttest, those in the treatment condition showed fewer depressive symptoms, less hopelessness, improved life satisfaction, and retrieval of more specific events. The findings suggest that practice in autobiographical memory for specific events may be among the components of life review that account for its effectiveness and could be a useful tool in psychotherapy with older adults.

Are old people more depressed? Cross-sectional data on Center for Epidemiological Studies Depression Scale factors.

Age differences on the 20-item Center for Epidemiological Studies Depression Scale (CES-D) were examined for 4 age-cohort groups: 20-39 years (n = 548), 40-54 years (n = 218), 55-69 years (n = 352), and 70-98 years (n = 212). On total CES-D, there was a significant age effect and quadratic trend, with means for the middle aged least and those for the oldest most elevated. On 4 CES-D subscales--Depressed Mood, Psychomotor Retardation, Lack of Well-being (i.e., reverse-scored items), and Interpersonal Difficulties--the oldest group scored highest only on lack of well-being. Somatic symptoms of depression were not elevated. Young adults scored highest on depressed mood. Adults who are now old were not generally characterized by elevated self-reports of depressive symptoms; however, on items asking whether the respondent has a hopeful outlook, those aged 70 and older were more likely to endorse a lack of such positive feelings.

Mid- and late-life diabetes in relation to the risk of dementia: a population-based twin study.

OBJECTIVE—We aimed to verify the association between diabetes and the risk of dementia, Alzheimers disease, and vascular dementia in twins and to explore whether genetic and early-life environmental factors could contribute to this association. RESEARCH DESIGN AND METHODS—This study included 13,693 twin individuals aged ≥65 years. Dementia was diagnosed according to DSM-IV (Diagnostic Manual of Mental Disorders, 4th ed.) criteria. Information on diabetes was collected from the inpatient registry and self- or informant-reported history of diabetes. Data were analyzed following two strategies: 1) unmatched case-control analysis for all participants using generalized estimating equation (GEE) models and 2) cotwin matched case-control analysis for dementia-discordant twin pairs using conditional logistic regression. RESULTS—Of all participants, 467 were diagnosed with dementia, including 292 with Alzheimers disease and 105 with vascular dementia, and an additional 170 were diagnosed with questionable dementia. Diabetes was present in 1,396 subjects. In GEE models, diabetes was associated with adjusted odds ratios (ORs) (95% CI) of 1.89 (1.51–2.38) for dementia, 1.69 (1.16–2.36) for Alzheimers disease, and 2.17 (1.36–3.47) for vascular dementia. Compared with late-life diabetes (onset age ≥65 years), the risk effect of mid-life diabetes (onset age <65 years) on dementia was stronger. Conditional logistic analysis of 210 dementia-discordant twin pairs led to ORs of 2.41 (1.05–5.51) and 0.68 (0.30–1.53) for dementia related to mid- and late-life diabetes, respectively. CONCLUSIONS—Diabetes increases the risk of Alzheimer disease and vascular dementia. The risk is stronger when diabetes occurs at mid-life than in late life. Genetic and early-life environmental factors might contribute to the late-life diabetes–dementia association but could not account for the mid-life diabetes–dementia association.

Neuroimaging findings in twins discordant for Alzheimer's disease

Data from computed tomography (CT) scans of 12 twin pairs in which one partner had Azheimer’s disease (AD) and the other partner is cognitively intact were analyzed to study structural brain features associated with AD while controlling for familial factors. Visual ratings and analysis of quantified areas and volumes indicated that AD twins showed more dilation of temporal horns, lateral ventricles and third ventricle, and more atrophy of temporal lobes, particularly in the anterior temporal/perisylvian area, than their healthy cotwins. Demented twins did not have smaller intracranial areas or overall brain volumes than their intact partners. The apolipoprotein σ-4 allele was associated with greater dilation of lateral ventricles and ventricular volume. Significant intrapair correlations were found for total intracranial area and volume, cerebellar area and white matter lesions.

Complete ascertainment of dementia in the Swedish Twin Registry: the HARMONY study

The purpose of this report is to describe the Study of Dementia in Swedish Twins (known as HARMONY), including procedures for complete ascertainment of all cases of Alzheimers disease (AD) and other dementias in 14,435 individuals aged 65 and older from the national Swedish twin registry. Telephone cognitive screening identified 11.5% as positive for cognitive dysfunction. Clinical diagnoses were completed for 1557 individuals, including individuals who screened positive, their twin partners, and a sample of normal controls. Estimated prevalence of dementia ranged from 1.4% for age 65-69 to 29.2% for age 90 and older. Concordance rates for Alzheimers disease were 59% for monozygotic twins, 32% for like-sexed, and 24% for unlike-sexed dizygotic twins. Among monozygotic twins where both twins had Alzheimers disease, the within pair difference in age of onset ranged from both becoming demented in the same year to 7 years difference in onset.