Margaret Gatz

University of Southern California, Los Ángeles, California, United States

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Publications (247)947.25 Total impact

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    ABSTRACT: Introduction: We asked whether anxiety is associated with prospective risk of dementia, and the extent to which genetic influences mediate this association. Methods: Nondemented twins (n = 1082) from the Swedish Adoption Twin Study of Aging completed an assessment of anxiety symptoms in 1984 and were followed for 28 years. Results: Baseline anxiety score, independent of depressive symptoms, was significantly associated with incident dementia over follow-up (hazard ratio [HR] = 1.04; 95% confidence interval [CI] = 1.01-1.06). There was 48% increased risk of becoming demented for those who had experienced high anxiety at any time compared with those who had not. In co-twin analyses, the association between anxiety symptoms and dementia was greater for dizygotic (HR = 1.11; 95% CI = 1.02-1.20) compared with monozygotic twins (HR = 1.06; 95% CI = 0.95-1.20), indicating genetic mediation. Discussion: Anxiety symptoms were associated with increased risk of dementia. Genetic factors common to dementia and anxiety partially mediated this association.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 11/2015; DOI:10.1016/j.jalz.2015.09.008 · 12.41 Impact Factor
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    ABSTRACT: Despite emerging interest in gene-environment interaction (GxE) effects, there is a dearth of studies evaluating its potential relevance apart from specific hypothesized environments and biometrical variance trends. Using a monozygotic within-pair approach, we evaluated evidence of G×E for body mass index (BMI), depressive symptoms, and cognition (verbal, spatial, attention, working memory, perceptual speed) in twin studies from four countries. We also evaluated whether APOE is a 'variability gene' across these measures and whether it partly represents the 'G' in G×E effects. In all three domains, G×E effects were pervasive across country and gender, with small-to-moderate effects. Age-cohort trends were generally stable for BMI and depressive symptoms; however, they were variable-with both increasing and decreasing age-cohort trends-for different cognitive measures. Results also suggested that APOE may represent a 'variability gene' for depressive symptoms and spatial reasoning, but not for BMI or other cognitive measures. Hence, additional genes are salient beyond APOE.
    Behavior Genetics 11/2015; DOI:10.1007/s10519-015-9761-3 · 3.21 Impact Factor
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    ABSTRACT: Methods: Through online recruitment, 1061 participants aged 30 to 98 answered two different depression scales, and 1065 participants answered multiple measures of subjective health. Rational and configural methods of harmonization were applied, using the crosswalk sample to determine their success; and empirical item response theory (IRT) methods were applied in order empirically to compare items from different measures as answered by the same person. Results: For depression, IRT worked well to provide a conversion table between different measures. The rational method of extracting semantically matched items from each of the two scales proved an acceptable alternative to IRT. For subjective health, only configural harmonization was supported. The subjective health items used in most studies form a single robust factor. Conclusion: Caution is required in aging research when pooling data across studies using different measures of the same construct. Of special concern are response scales that vary widely in the number of response options, especially if the anchors are asymmetrical. A crosswalk sample that has completed items from each of the measures being harmonized allows the investigator to use empirical approaches to identify flawed assumptions in rational or configural approaches to harmonizing.
    Experimental Aging Research 11/2015; 41(5):475-495. DOI:10.1080/0361073X.2015.1085748 · 0.92 Impact Factor
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    Alzheimer disease and associated disorders 10/2015; DOI:10.1097/WAD.0000000000000114 · 2.44 Impact Factor
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    ABSTRACT: We examined the extent to which tauopathy distribution, as determined by Braak staging, might be predicted by various risk factors in older individuals. The Swedish Twin Registry provided extensive information on neuropsychological function, lifestyle, and cardiovascular risk factors of 128 patients for whom autopsy data including Braak staging were available. Logistic regression was used to develop a prognostic model that targeted discrimination between Braak stages 0 to II and III to VI. The analysis showed that Braak stages III to VI were significantly predicted by having 1 or more APOE ε4 alleles, older age, high total cholesterol, absence of diabetes and cardiovascular disease, and poorer scores on the Wechsler Adult Intelligence Score Information test, verbal fluency, and recognition memory but better verbal recall. The algorithm predicted Braak stages III to VI well (receiver-operating characteristic area under curve, 0.897; 95% confidence interval, 0.842-0.951). Using a cutoff of 50% risk or more, the sensitivity was 85%, the specificity was 70%, and the negative predictive value was 69%. This study demonstrates that tauopathy distribution can be accurately predicted using a combination of antemortem patient data. These results provide further insight into tauopathy development and AD-related disease mechanisms and suggest a prognostic model that predicts the spread of neurofibrillary tangles above the transentorhinal stage.
    10/2015; 74(11):1061-1070. DOI:10.1097/NEN.0000000000000251
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    ABSTRACT: From the IGEMS Consortium, data were available from 26,579 individuals aged 23 to 102 years on 3 subjective health items: self-rated health (SRH), health compared to others (COMP), and impact of health on activities (ACT). Marital status was a marker of environmental resources that may moderate genetic and environmental influences on subjective health. Results differed for the 3 subjective health items, indicating that they do not tap the same construct. Although there was little impact of marital status on variance components for women, marital status was a significant modifier of variance in all 3 subjective health measures for men. For both SRH and ACT, single men demonstrated greater shared and nonshared environmental variance than married men. For the COMP variable, genetic variance was greater for single men vs. married men. Results suggest gender differences in the role of marriage as a source of resources that are associated with subjective health.
    Behavior Genetics 10/2015; DOI:10.1007/s10519-015-9758-y · 3.21 Impact Factor
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    ABSTRACT: A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m 2 in childhood and adolescence and up to 0.2 kg/m 2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
    Twin Research and Human Genetics 09/2015; 18(5):1-14. DOI:10.1017/thg.2015.57 · 2.30 Impact Factor
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    ABSTRACT: Although the Swedish Adoption Twin of Aging (SATSA) has been used to investigate phenotypic stability of late life depressive symptoms, the biometric processes underlying this stability have not been studied. Under a reciprocal effects modeling framework, we used SATSA twins' Center for Epidemiologic Studies Depression (CES-D) Scale data across 5 waves (from 1987-2007) to test whether the reciprocal exchange between twins within a family and their nonshared environments (P<=>E) promote the accumulation of gene-environment correlation (rGE) over time. The model generates increasing rGE that produces subsequent stable environmental differences between twins within a family-a process hypothesized to explain stability in chronic late life depressive symptoms. Widowhood is included as a stressful life experience that may introduce an additional nonshared source of variability in CES-D scores. Genetic effects and nonshared environmental effects are primary sources of stability of late life depressive symptoms without evidence of underlying rGE processes. Additionally, widowhood explained stable differences in CES-D scores between twins within a family up to 3 years after spousal loss.
    Behavior Genetics 08/2015; DOI:10.1007/s10519-015-9733-7 · 3.21 Impact Factor
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    ABSTRACT: In this study, we explored the association between the personality traits, neuroticism and introversion, and risk of Parkinson disease (PD). A population-based cohort study was conducted using questionnaire data from the Swedish Twin Registry for twins born 1926-1958 (n > 29,000). Personality traits were assessed in 1973 by a short form of Eysenck's Personality Inventory. The cohort was followed from 1974 to 2012 through Swedish patient and cause of death registers for PD ascertainment. Cox proportional hazards regression was used to estimate subsequent risk of PD, adjusting for attained age, sex and smoking. A mediation analysis was performed to further explore the role of smoking in the relationship between personality trait and PD. Confounding by familial factors was explored using a within-pair analysis. During a mean follow-up time of 36.8 years, 197 incident PD cases were identified. Both neuroticism and introversion were associated with an increased risk of PD after adjustment. Smoking was a significant mediator in the relationship between personality traits and PD that partly accounted for the effect of introversion, whereas it acted as a suppressor for the effect of neuroticism on PD risk. In the within-pair analyses, associations for neuroticism and introversion were attenuated. In conclusion, our study provides evidence that neuroticism is associated with an increased risk of PD that is in part suppressed by smoking. There was a weak association between introversion and PD and this effect was at least partly mediated through smoking. The observed effects may partly be explained by familial factors shared by twins.
    European Journal of Epidemiology 07/2015; DOI:10.1007/s10654-015-0062-1 · 5.34 Impact Factor
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    ABSTRACT: For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m 2 ) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
    Twin Research and Human Genetics 05/2015; 10(10):1017. DOI:10.1017/thg.2015.29 · 2.30 Impact Factor
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    ABSTRACT: Midlife alcohol consumption (beer, wine, and spirits) was examined in relation to dementia incidence over 43 years. Participants were 12,326 members of the population-based Swedish Twin Registry born during 1907-1925 who responded to items about alcohol consumption in 1967/1970, subsequently classified as nondrinking (0 grams of ethanol per day), light (1-5g/d), moderate (5-12g/d), heavy (12-24g/d), and very heavy (>24g/d) drinking. Dementia was identified from the National Patient and Cause of Death Registries. Cox proportional hazard models adjusted for cluster-correlated data were used in cohort analyses. Conditional logistic regression (dementia-discordant pairs) and mixed effects models (dementia-concordant pairs) were used in twin analyses. Overall, nondrinkers did not differ from light drinkers in dementia risk. Heavy drinking (hazard ratio = 1.10, p = .028) and very heavy drinking (hazard ratio = 1.18, p = .033) were associated with increased dementia risk controlling for sociodemographic, lifestyle, and cardiovascular factors. More alcohol from spirits was related to increased risk of dementia, whereas more alcohol from wine with decreased risk, although the association for wine reversed direction at high amounts. Relative to co-twins drinking light amounts, moderate-to-heavy drinking twins had (a) greater risk of dementia by 57% (p = .006, 300% in monozygotic pairs only) and (b) reduced time to dementia by 4.76 years (p = .019, 4.78 years in monozygotic pairs only). Averaging more than 12 grams of alcohol per day may increase risk of dementia. Alcohol from spirits appears particularly important for the increased dementia risk. Genetic and/or familial factors do not explain these associations. Alcohol use reduction may be a useful population-wide intervention strategy. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please email:
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 04/2015; 70(10). DOI:10.1093/gerona/glv038 · 5.42 Impact Factor
  • Sarah J Barber · Mara Mather · Margaret Gatz ·
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    ABSTRACT: Stereotype threat can impair older adults' performance on clinical assessments for cognitive decline. We examined why this occurs. Based upon the regulatory focus account of stereotype threat, we predicted that the effects of stereotype threat should depend upon the assessments' reward structure. Stereotype threat should be associated with poor performance when the assessment emphasizes gaining correct answers, but not when it emphasizes avoiding mistakes. Healthy older adults completed a series of mental status examinations. Half of the participants completed these examinations under stereotype threat about their cognitive abilities. Monetary incentives were also manipulated. For half of the participants correct responding led to gains. For the remaining participants incorrect responding/forgetting led to losses. Consistent with the regulatory focus account, stereotype threat was associated with poor performance when the mental status examinations had a gains-based structure, but not when they had a losses-based structure. Older adults respond to stereotype threat by becoming vigilant to avoid the losses that will make them their worst. Researchers and clinicians can capitalize on this motivational change to combat stereotype threat's negative effects. By using a loss-avoidance frame, stereotype threat's negative effects can be attenuated or even eliminated. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail:
    The Journals of Gerontology Series B Psychological Sciences and Social Sciences 03/2015; DOI:10.1093/geronb/gbv009 · 3.21 Impact Factor
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    ABSTRACT: This study aimed to estimate the magnitude of geographical variation in dementia rates and suggest explanations for this variation. Small-area studies are scarce, and none has adequately investigated the relative contribution of genetic and environmental factors to the distribution of dementia. We present 2 complementary small-area hierarchical Bayesian disease-mapping studies using the comprehensive Swedish Twin Registry (n = 27,680) and the 1932 Scottish Mental Survey cohort (n = 37,597). The twin study allowed us to examine the effect of unshared environmental factors. The Scottish Mental Survey study allowed us to examine various epochs in the life course-approximately age 11 years and adulthood. We found a 2- to 3-fold geographical variation in dementia odds in Sweden, after twin random effects-likely to capture genetic and shared environmental variance-were removed. In Scotland, we found no variation in dementia odds in childhood but substantial variation, following a broadly similar pattern to Sweden, by adulthood. There is geographical variation in dementia rates. Most of this variation is likely to result from unshared environmental factors that have their effect in adolescence or later. Further work is required to confirm these findings and identify any potentially modifiable socioenvironmental risk factors for dementia responsible for this geographical variation in risk. However, if these factors do exist and could be optimized in the whole population, our results suggest that dementia rates could be halved.
    Epidemiology (Cambridge, Mass.) 01/2015; 26(2). DOI:10.1097/EDE.0000000000000230 · 6.20 Impact Factor
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    M Alison Balbag · Nancy L Pedersen · Margaret Gatz ·
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    ABSTRACT: Increasing evidence supports that playing a musical instrument may benefit cognitive development and health at young ages. Whether playing an instrument provides protection against dementia has not been established. In a population-based cotwin control study, we examined the association between playing a musical instrument and whether or not the twins developed dementia or cognitive impairment. Participation in playing an instrument was taken from informant-based reports of twins' leisure activities. Dementia diagnoses were based on a complete clinical workup using standard diagnostic criteria. Among 157 twin pairs discordant for dementia and cognitive impairment, 27 pairs were discordant for playing an instrument. Controlling for sex, education, and physical activity, playing a musical instrument was significantly associated with less likelihood of dementia and cognitive impairment (odds ratio [OR] = 0.36 [95% confidence interval 0.13-0.99]). These findings support further consideration of music as a modifiable protective factor against dementia and cognitive impairment.
    International Journal of Alzheimer's Disease 12/2014; 2014:836748. DOI:10.1155/2014/836748
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    ABSTRACT: The current study investigated how participant aging may influence mode effects, wherein individuals report less negative and more positive psychosocial functioning with data collection modes that have greater (vs. less) direct contact with interviewers (e.g., in-person interviews vs. telephone interviews). Using two longitudinal datasets, the Later Life Study of Social Exchanges (LLSSE) and Swedish Adoption/Twin Study of Aging (SATSA), we tested how mode effects may vary with cohort (baseline age differences) and maturational development (longitudinal change). In Study 1, LLSSE participants (65-90 years old) completed in-person and telephone interviews assessing negative and positive aspects of psychosocial functioning across two years. The data collection mode with greater direct contact with interviewers (in-person interviews) was associated with reporting less negative and more positive psychosocial functioning compared to the mode with less direct contact (telephone interviews). These mode effects were more pronounced with older baseline age, but only for the negative psychosocial measures. Mode effects also became stronger over time for reports of negative affect. In Study 2, SATSA participants (38-86 years old) completed mailed questionnaires and questionnaires collected in-person that assessed depressive symptoms and positive affect across 18 years. Consistent with Study 1, participants reported fewer depressive symptoms and more positive affect with greater (vs. less) direct contact with interviewers (questionnaires collected in-person vs. mailed questionnaires). For reports of depressive symptoms, but not positive affect, mode effects were more pronounced with age and time. Together, the results underscore how mode effects may contribute to inconsistent findings in the socioemotional aging literature.
    Psychology and Aging 10/2014; 30(1). DOI:10.1037/a0038502 · 2.73 Impact Factor
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    ABSTRACT: Objective: The goal of this research was to evaluate nutrition education targeting Latinas, a group at particular risk of obesity and diabetes, which predict to later life cardiovascular disease and dementia. Method: Culturally tailored, theory-based nutrition education was provided to Mexican origin Latinas aged 48 to 84. The randomized design compared participants in workshops incorporating the connection between dietary fat and brain health, participants in workshops focusing only on dietary fat and heart health, a waitlist control group, and a posttest only control group. Results: Among those assigned to either intervention, there was statistically significant gain in health literacy, knowledge about dietary fat, and behaviors to reduce dietary fat compared with waitlist control. There was no difference in outcomes between those given the module about diet and brain health and those not provided that module. Discussion: A program to encourage dietary fat modification in Latinas proved feasible and modestly effective.
    Journal of Aging and Health 09/2014; 27(1). DOI:10.1177/0898264314549660 · 1.56 Impact Factor
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    ABSTRACT: Background: The etiology of Parkinson's disease (PD) remains unclear, and environmental risk-factors such as occupation have attracted interest. Objective: The goal was to investigate occupational complexity in relation to PD. Methods: We conducted a population-based cohort study based on the Swedish Twin Registry that included 28,778 twins born between 1886 and 1950. We identified 433 PD cases during the study period. Data on occupation were collected from either the 1970 or 1980 Swedish census, and occupational complexity was assessed via a job exposure matrix. Cox proportional hazard regression analyses with age as the underlying time scale were used to assess PD risk as a function of the three domains of occupational complexity: data, people, and things. Sex and smoking were included as covariates. Analyses stratified by twin pair were conducted to test for confounding by familial factors. Results: High occupational complexity with data and people was associated with increased risk overall (Hazard Ratio [HR] = 1.07, 95% confidence interval [CI] 1.02-1.14, and HR = 1.10, 95% CI 1.01-1.21, respectively), and in men (HR = 1.08, 95% CI 1.01-1.16, and HR = 1.15, 95% CI 1.03-1.28, respectively). Complexity with things was not associated with risk of PD. When the analyses were stratified by twin pair, the HRs for occupational complexity with data and people were attenuated in men. Conclusions: High complexity of work with data and people is related to increased risk of PD, particularly in men. The attenuation of risk observed in the twin pair-stratified analyses suggests that the association may partly be explained by familial factors, such as inherited traits contributing to occupational selection or other factors shared by twins.
    PLoS ONE 09/2014; 9(9):e106676. DOI:10.1371/journal.pone.0106676 · 3.23 Impact Factor
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    ABSTRACT: The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry) is a comprehensive registry of White male twin pairs born in the USA between 1917 and 1927, both of the twins having served in the military. The purpose was medical research and ultimately improved clinical care. The cohort was assembled in the early 1960s with identification of approximately 16 000 twin pairs, review of service records, a brief mailed questionnaire assessing zygosity, and a health survey largely comparable to questionnaires used at that time with Scandinavian twin registries. Subsequent large-scale data collection occurred in 1974, 1985 and 1998, repeating the health survey and including information on education, employment history and earnings. Self-reported data have been supplemented with mortality, disability and medical data through record linkage. Potential collaborators should access the study website [] or e-mail the Medical Follow-up Agency at [[email protected] /* */]. Questionnaire data are being prepared for future archiving with the National Archive of Computerized Data on Aging (NACDA) at the Inter-University Consortium for Political and Social Research (ICPSR), University of Michigan, MI. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 09/2014; 44(3). DOI:10.1093/ije/dyu181 · 9.18 Impact Factor
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    Alzheimer's and Dementia 07/2014; 10(4):P751. DOI:10.1016/j.jalz.2014.05.1425 · 12.41 Impact Factor
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    Alzheimer's and Dementia 07/2014; 10(4):P871. DOI:10.1016/j.jalz.2014.05.1746 · 12.41 Impact Factor

Publication Stats

9k Citations
947.25 Total Impact Points


  • 1992-2015
    • University of Southern California
      • Department of Psychology
      Los Ángeles, California, United States
  • 2004-2014
    • University of Castilla-La Mancha
      • Faculty of Medicine of Albacete
      Ciudad Real, Castille-La Mancha, Spain
    • Jönköping University
      • Institute of Gerontology
      Jönköping, Jönköping, Sweden
  • 1989-2014
    • Karolinska Institutet
      • • Department of Medical Epidemiology and Biostatistics
      • • Institutet för miljömedicin - IMM
      • • Institutionen för klinisk neurovetenskap
      Solna, Stockholm, Sweden
  • 1987-2014
    • University of California, Los Angeles
      • • Department of Psychology
      • • Department of Neurology
      Los Ángeles, California, United States
  • 2004-2011
    • University of Gothenburg
      • Department of Psychology
      Goeteborg, Västra Götaland, Sweden
  • 2007
    • Universidad Autónoma de Madrid
      • Departamento de Psicología Biológica y de la Salud
      Madrid, Madrid, Spain
  • 2003
    • National University (California)
      San Diego, California, United States
    • Indiana University Southeast
      • School of Social Sciences
      New Albany, IN, United States
  • 2002-2003
    • University of California, San Diego
      • Department of Psychiatry
      San Diego, CA, United States
    • University of California, Riverside
      • Department of Psychology
      Riverside, CA, United States
  • 2001
    • University of California, Irvine
      • Department of Psychology and Social Behavior
      Irvine, CA, United States
  • 1979
    • Loyola University Maryland
      Baltimore, Maryland, United States