Investigating Genetic and Environmental Substrates of the Relationship between Positive Mental Health and Biological Aging-A Study Protocol.

BACKGROUND: The Italian National Institute of Health (Istituto Superiore di Sanità) funded a 30-month project (July 2021-January 2024) to conduct a twin study of the relationships between Positive Mental Health (PMH) and cellular longevity. Only a few previous studies have focused on the biomarkers of aging in relation to psychological well-being, and none of them exploited the potential of the twin design. METHOD: In this project, following the standard procedures of the Italian Twin Registry (ITR), we aim to recruit 200 adult twin pairs enrolled in the ITR. They are requested to complete a self-report questionnaire battery on PMH and to undergo a blood withdrawal for the assessment of aging biomarkers, i.e., telomere length and mitochondrial DNA functionality. The association between psychological and aging biomarker measures will be assessed, controlling for genetic and familial confounding effects using the twin study design. RESULTS AND CONCLUSIONS: Biomarker assays are underway. Once data are available for the total study sample, statistical analyses will be performed. The project's results may shed light on new mechanisms underlying the mind-body connection and may prove helpful to promote psychological well-being in conjunction with biological functioning.

Attitude and concerns of healthy individuals regarding post-mortem brain donation. A qualitative study on a nation-wide sample in Italy.

BACKGROUND: Collecting post-mortem brain tissue is essential, especially from healthy "control" individuals, to advance knowledge on increasingly common neurological and mental disorders. Yet, healthy individuals, on which this study is focused, are still understudied. The aim of the study was to explore, among healthy potential brain donors and/or donors' relatives, attitude, concerns and opinion about post-mortem brain donation (PMBD). METHODS: A convenience sampling of the general population (twins and their non-twin contacts) was adopted. From June 2018 to February 2019, 12 focus groups were conducted in four Italian cities: Milan, Turin, Rome and Naples, stratified according to twin and non-twin status. A qualitative content analysis was performed with both deductive and inductive approaches. Emotional interactions analysis corroborated results. RESULTS: One hundred and three individuals (49-91 yrs of age) participated. Female were 60%. Participants had scarse knowledge regarding PMBD. Factors affecting attitude towards donation were: concerns, emotions, and misconceptions about donation and research. Religion, spirituality and secular attitude were implied, as well as trust towards research and medical institutions and a high degree of uncertainty about brain death ascertainment. Family had a very multifaceted central role in decision making. A previous experience with neurodegenerative diseases seems among factors able to favour brain donation. CONCLUSIONS: The study sheds light on healthy individuals' attitudes about PMBD. Brain had a special significance for participants, and the ascertainment of brain death was a source of debate and doubt. Our findings emphasise the importance of targeted communication and thorough information to promote this kind of donation, within an ethical framework of conduct. Trust in research and health professionals emerged as an essential factor for a collaborative attitude towards donation and informed decision making in PMBD.

The Italian Twin Registry: An Update at 18 Years From Its Inception.

The Italian Twin Registry (ITR), established in 2001, is a population-based registry of voluntary twins. To date, it consists of approximately 29,000 twins who gave their consent to participate in the studies proposed by the ITR research group. The database comprises 11,500 monozygotic and 16,700 dizygotic twins resident throughout the country and belonging to a wide age range (from 0 to 95 years, mean 36.8 years). This article provides an overview of the recruitment strategies along with the major phenotypes investigated during an 18 years' research period. Over the years, several self-reported questionnaire data were collected, together with saliva/blood samples and measurements taken during in-person interviews or outpatient clinical examinations. Mental and behavioral phenotypes as well as atherosclerotic traits were studied in depth across different age groups. A birth cohort of twins was established and followed up. Novel research hypotheses are also being tested in ongoing projects. The ITR is involved in international studies in collaboration with other twin registries and represents a valuable resource for national and international research initiatives regarding a broad spectrum of health-related characteristics.

Genetic influence on femoral plaque and its relationship with carotid plaque: an international twin study.

To disentangle genetic and environmental influences on the development of femoral plaques using a population of adult twins. To evaluate the potential role of shared genetic and environmental factors in the co-occurrence of femoral and carotid plaques. The sample included 566 twins belonging to 164 monozygotic (MZ) and 119 dizygotic (DZ) twin pairs, who underwent peripheral arterial assessment by B-mode ultrasound in different centers. The variance in femoral plaques onset was due to genetic factors and the remaining 50% was explained by common (15%) and unique (35%) environmental factors. Findings on sidedness and number of femoral plaques indicated that also these traits were mainly under genetic control. No effect of common environment was found on plaques composition, and variability of this trait was explained by genetics (64%) and unique environment (36%). Covariation between the liabilities to carotid and femoral plaques was mainly attributed to shared genes (77%), with the remaining 23% explained by individual-specific environmental factors shared by the two districts. Inter-individual differences in plaque onset as well as in their number, sidedness and composition are mainly genetic in origin. The results on the cooccurrence of carotid and femoral plaque underline the genetic role in atherogenesis.

Femoral Artery Ultrasound Examination.

We compared intima-media thickness (IMT) and the prevalence of plaques in the common carotid artery (CCA) and common femoral artery (CFA) in apparently healthy participants. This multicenter study included 322 participants (59.9% female; age 20-78 years, mean 52.1 ± 15.3 years) who underwent Echo-color Doppler examination of the CCA and CFA bilaterally. Prevalence and composition of plaque were recorded. A significant ( P < .01) difference between mean CCA-IMT and mean CFA-IMT was detected (0.70 vs 0.73 mm). Plaque prevalence was significantly higher in the CFA compared to the CCA (40.7% vs 30.4%). Atherosclerotic plaques were found in both CFA and CCA in 46% of the cases, solely in CFA in 38%, and in CCA alone in 17%. The observed difference in plaque prevalence was even greater when only fibrolipid isolated plaques were considered (CFA 39.4% vs CCA 22.1%). In a healthy general population, atherosclerotic plaques were present in the CFA but not in the CCA in over one-third of the cases. Further studies must confirm whether ultrasonography of the CFA might be introduced in the screening protocols for cardiovascular risk assessment.

Genetic and environmental bases of the interplay between magical ideation and personality.

Sub-threshold psychotic symptoms are quite commonly present in general population. Among these, Magical Ideation (MI) has been proved to be a valid predictor of psychosis. However, the genetic and environmental influences on the interplay between MI and personality have not fully been explored. A total of 534 adult twins from the population-based Italian Twin Register were assessed for MI using the MI Scale (MIS) and for personality with the temperament and character inventory (TCI). A Multivariate Cholesky model was applied with Mx statistical program. The best-fitting model showed that additive genetic and unshared environmental factors explain approximately the same proportion of variance in MI, whereas a less strong genetic influence on personality traits emerged. Relevant correlations between MI and specific personality traits (novelty seeking, cooperativeness, self-directedness, self-transcendence) were found, suggesting shared influences for MI and these traits. Both genetic and environmental factors explained these correlations, with genetic factors playing a predominant role. Moderate-to-substantial genetic effects on MI and personality were found. Shared genetic and environmental effects underlie the phenotypic correlation between MI (psychosis-proneness) and personality traits, i.e. self-directedness (negative association) and self-transcendence (positive association), potentially representing predictive markers of psychosis liability related to schizotypy and personality.

An update on the Italian Twin Register: advances in cohort recruitment, project building and network development.

The Italian Twin Register has been in place for more than 10 years. Since its establishment, it has been focusing, on the one hand, on a continuous update of the existing information, and on the other hand, on new phenotypes and sample collection. Demographic data on about 140,000 twins have been updated using the municipality registries. The Italian Twin Register has been carrying out several new studies during the last few years. A birth cohort of twins, Multiple Births Cohort Study, has been started and the enrollment is ongoing. For this cohort, data on pregnancy and birth are collected, and periodical follow-ups are made. DNA is being collected for the twins and their parents. In the area of behavioral genetics, most efforts have been directed to psychological well being assessed with self-reported tools. Research on age-related traits continues with studies on arteriosclerosis development, early biomarkers in mild cognitive impairment, and the relation between lifestyle habits and mutagen sensitivity. The Italian Twin Register biobanking has grown in its size and in its know-how in terms of both technical issues and ethical procedures implementation. Furthermore, attitudes toward biobank-based research, together with willingness and motivation for donation, are being investigated. A valuable key resource for the Italian Twin Register is the possibility of linking twin data with disease registries. This approach has been yielding several important results, such as the recent study on the heritability of type 1 diabetes.

Clumsiness and psychopathology: causation or shared etiology? A twin study with the CBCL 6-18 questionnaire in a general school-age population sample.

In a sample of 398 twin pairs aged 8-17 belonging to the Italian Twin Registry we explored the extent to which physical clumsiness/motor problems covary with a broad spectrum of behavioral problems identified by the Child Behavior Checklist 6-18/DSM oriented scales, and the causes of such covariation. Only Anxiety and Attention Deficit Hyperactivity (ADH) Problems maintained significant correlation with Clumsiness after partialling out the effects of the other problem scales. By the co-twin control method we found no indication of clear, direct causal effect of Clumsiness upon Anxiety or ADH Problems, or vice versa. Twin bivariate analyses showed that the co-occurrence of motor problems and Anxiety/ADH Problems is best explained by genetic factors shared between Clumsiness and the behavioral problems phenotypes.