Commentary on "Same-Sex Marriage and Common Mental Health Diagnoses: A Sibling Comparison and Adoption Approach".

This is a commentary on "Same-sex Marriage and Common Mental Health Diagnoses: A Sibling Comparison and Adoption Approach" by Xu, Rahman, Hiyoshi, and Montgomery. It considers the advantages and disadvantages of the study design and the contribution the study makes to the scientific literature. Discussed are issues of phenotype accuracy especially with respect to sexual orientation and other potential confounds, and some comments on common misunderstandings of the meaning and implications of findings of genetic correlations to human behavior.