Bias in adoption based research: methodological and statistical implications for behavioral genetics

The present study investigated the methodological/statistical implications of adoptive parent knowledge for adoption methods used to estimate genetic and environmental contributions to individual differences. The sample used consisted of adoptees (n = 497) whose biological parents had been identified as either alcoholic, anti-social, or as a member of a control group in which neither alcoholism nor anti-social personality were diagnosed. The original purpose of the data set was content related in that it was intended to investigate genetic and environmental determinants of alcoholism and anti-social personality, as well as the interaction between genetic and environmental factors. The present study represents a methodological approach in that the data was used, not to predict alcoholism and anti-social personality, but rather, to determine whether estimates of genetic and environmental influences can be biased, either upward or downward, depending on whether the adoptive parent was cognizant of biological parent characteristics;Baron and Kenny\u27s (1986) models of moderation, mediation, and mediated moderation were used to identify potential pathways through which adoptive parent knowledge might bias the estimates of the relative contribution of genes and environment to individual differences in adoptee outcomes. Adoptee outcomes were represented by both adaptive and maladaptive behaviors and were as follows: child conduct disorder symptoms, child attention deficit disorder symptoms, aggression symptoms, adolescent self-esteem, adoptee alcohol use symptoms, and adoptee adult anti-social personality disorder;The results showed that bias does exist if one does not include estimations of adoptive parent knowledge. For females, environmental influences were underestimated, whereas for males genetic influences were underestimated. The findings were discussed within the context of already existing confounds identified in behavioral genetics research (e.g., selective placement, assortative mating, additive-nonadditive genetic effects, twin assimilation) and the potential bias these confounds might produce in estimating genetic and environmental main and/or interaction effects

Attachment as an organizer of behavior: implications for substance abuse problems and willingness to seek treatment

BACKGROUND: Attachment theory allows specific predictions about the role of attachment representations in organizing behavior. Insecure attachment is hypothesized to predict maladaptive emotional regulation whereas secure attachment is hypothesized to predict adaptive emotional regulation. In this paper, we test specific hypotheses about the role of attachment representations in substance abuse/dependence and treatment participation. Based on theory, we expect divergence between levels of maladaptive functioning and adaptive methods of regulating negative emotions. METHODS: Participants for this study consist of a sample of adoptees participating in an ongoing longitudinal adoption study (n = 208). The Semi-Structured Assessment of the Genetics of Alcohol-II [41] was used to determine lifetime substance abuse/dependence and treatment participation. Attachment representations were derived by the Adult Attachment Interview [AAI; [16]]. We constructed a prior contrasts reflecting theoretical predictions for the association between attachment representations, substance abuse/dependence and treatment participation. RESULTS: Logistic regression was used to test our hypotheses. As predicted, individuals classified as dismissing, preoccupied or earned-secure reported the highest rates of substance abuse/dependence. Individuals classified as dismissing reported significantly lower rates of treatment participation despite their high rates of substance abuse/dependence. As expected, the continuous-secure group reported lowest rates of both substance abuse/dependence and treatment participation. CONCLUSION: The findings from this study identify attachment representations as an influential factor in understanding the divergence between problematic substance use and treatment utilization. The findings further imply that treatment may need to take attachment representations into account to promote successful recovery

Measuring quality of life in muscular dystrophy

OBJECTIVES: The objectives of this study were to develop a conceptual model of quality of life (QOL) in muscular dystrophies (MDs) and review existing QOL measures for use in the MD population. METHODS: Our model for QOL among individuals with MD was developed based on a modified Delphi process, literature review, and input from patients and patient advocacy organizations. Scales that have been used to measure QOL among patients with MD were identified through a literature review and evaluated using the COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) checklist. RESULTS: The Comprehensive Model of QOL in MD (CMQM) captures 3 broad domains of QOL (physical, psychological, and social), includes factors influencing self-reported QOL (disease-related factors, support/resources, and expectations/aspirations), and places these concepts within the context of the life course. The literature review identified 15 QOL scales (9 adult and 6 pediatric) that have been applied to patients with MD. Very few studies reported reliability data, and none included data on responsiveness of the measures to change in disease progression, a necessary psychometric property for measures included in treatment and intervention studies. No scales captured all QOL domains identified in the CMQM model. CONCLUSIONS: Additional scale development research is needed to enhance assessment of QOL for individuals with MD. Item banking and computerized adaptive assessment would be particularly beneficial by allowing the scale to be tailored to each individual, thereby minimizing respondent burden

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Perceived quality of life among caregivers of children with a childhood-onset dystrophinopathy: a double ABCX model of caregiver stressors and perceived resources

Background: Duchenne and Becker muscular dystrophies, collectively referred to as dystrophinopathies, are recessive X-linked disorders characterized by progressive muscle weakness and ultimately cardiac and respiratory failure. Immediate family members are often primary caregivers of individuals with a dystrophinopathy. Methods: We explored the impact of this role by inviting primary caregivers (n = 209) of males diagnosed with childhood-onset dystrophinopathy who were identified by the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) to complete a mailed questionnaire measuring perceived social support and stress, spirituality, and family quality of life (FQoL). Bivariate and multivariate analyses examined associations between study variables using the Double ABCX model as an analytic framework. Results: Higher stressor pile-up was associated with lower perceived social support (r = -0.29, p 0.05). FQoL was positively associated with all support measures (correlations ranged from: 0.25 to 0.58, p-values 0.01-0.001) and negatively associated with perceived stress and control (r = -0.49, p <.001). The association between stressor pile-up and FQoL was completely mediated through global perceived social support, supportive family relationships, and perceived stress and control; supportive non-family relationships did not remain statistically significant after controlling for other mediators. Conclusions: Findings suggest caregiver adaptation to a dystrophinopathy diagnosis can be optimized by increased perceived control, supporting family resources, and creation of a healthy family identity. Our findings will help identify areas for family intervention and guide clinicians in identifying resources that minimize stress and maximize family adaptation.CDC [5U01DD000831, 5U01DD000187, 5U01DD000189, 5U01DD000191, 5U01DD000190]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Bias in adoption based research: methodological and statistical implications for behavioral genetics

The present study investigated the methodological/statistical implications of adoptive parent knowledge for adoption methods used to estimate genetic and environmental contributions to individual differences. The sample used consisted of adoptees (n = 497) whose biological parents had been identified as either alcoholic, anti-social, or as a member of a control group in which neither alcoholism nor anti-social personality were diagnosed. The original purpose of the data set was content related in that it was intended to investigate genetic and environmental determinants of alcoholism and anti-social personality, as well as the interaction between genetic and environmental factors. The present study represents a methodological approach in that the data was used, not to predict alcoholism and anti-social personality, but rather, to determine whether estimates of genetic and environmental influences can be biased, either upward or downward, depending on whether the adoptive parent was cognizant of biological parent characteristics;Baron and Kenny's (1986) models of moderation, mediation, and mediated moderation were used to identify potential pathways through which adoptive parent knowledge might bias the estimates of the relative contribution of genes and environment to individual differences in adoptee outcomes. Adoptee outcomes were represented by both adaptive and maladaptive behaviors and were as follows: child conduct disorder symptoms, child attention deficit disorder symptoms, aggression symptoms, adolescent self-esteem, adoptee alcohol use symptoms, and adoptee adult anti-social personality disorder;The results showed that bias does exist if one does not include estimations of adoptive parent knowledge. For females, environmental influences were underestimated, whereas for males genetic influences were underestimated. The findings were discussed within the context of already existing confounds identified in behavioral genetics research (e.g., selective placement, assortative mating, additive-nonadditive genetic effects, twin assimilation) and the potential bias these confounds might produce in estimating genetic and environmental main and/or interaction effects.</p

Assessing community variation and randomness in public health indicators

Abstract Background Evidence-based health indicators are vital to needs-based programming and epidemiological planning. Agencies frequently make programming funds available to local jurisdictions based on need. The use of objective indicators to determine need is attractive but assumes that selection of communities with the highest indicators reflects something other than random variability from sampling error. Methods The authors compare the statistical performance of two heterogeneity measures applied to community differences that provide tests for randomness and measures of the percentage of true community variation, as well as estimates of the true variation. One measure comes from the meta-analysis literature and the other from the simple Pearson chi-square statistic. Simulations of populations and an example using real data are provided. Results The measure based on the simple chi-square statistic seems superior, offering better protection against Type I errors and providing more accurate estimates of the true community variance. Conclusions The heterogeneity measure based on Pearson's χ2 should be used to assess indices. Methods for improving poor indices are discussed.</p