Genetic Influence on Social Support: A Twin Study.

Social support is often considered an environmental factor affecting health, especially in aging populations. However, its genetic underpinnings suggest a more complex origin. This study investigates the heritability of social support through applying a threshold model on data of a large adult sample of twins ( = 8019) from the Netherlands Twin Register, collected between 2009 and 2011.

Same-Sex Relationships and Criminal Behavior: A Total Population Study in The Netherlands.

Sexual minority groups experience elevated risk across a range of adverse outcomes. Previous studies from the USA showed that these risks include contact with the criminal justice system for sexual minority females but not for males. This study examined whether this relationship between sexual minority status and criminal behavior was also found in a more secular country like the Netherlands with more progressive attitudes toward sexual minorities.

Direct and Indirect Genetic Effects on Aggression.

Background: Family members resemble each other in their propensity for aggression. In twin studies, approximately 50% of the variance in aggression can be explained by genetic influences. However, if there are genotype-environment correlation mechanisms, such as environmental manifestations of parental and sibling genotypes, genetic influences may partly reflect environmental influences.

Home-based exergaming to treat gait and balance disorders in patients with Parkinson's disease: A phase II randomized controlled trial.

Background: Exergaming has been proposed to improve gait and balance disorders in Parkinson's disease (PD) patients. We aimed to assess the efficacy of a home-based, tailored, exergaming training system designed for PD patients with dopa-resistant gait and/or balance disorders in a controlled randomized trial.

Methods: We recruited PD patients with dopa-resistant gait and/or balance disorders.

The Co-Twin Control Design: Implementation and Methodological Considerations.

Establishing causal relationships in observational studies is an important step in research and policy decision making. The association between an exposure and an outcome can be confounded by multiple factors, often making it hard to draw causal conclusions. The co-twin control design (CTCD) is a powerful approach that allows for the investigation of causal effects while controlling for genetic and shared environmental confounding factors.