psychiatric twin study
Research design comparing psychiatric traits between identical and fraternal twins to estimate genetic and environmental contributions.
Full Definition
A classical epidemiological study design in psychiatric genetics that compares the concordance of psychiatric disorders or traits between monozygotic (identical) and dizygotic (fraternal) twin pairs to decompose the relative contributions of genetic and environmental factors. The method relies on the assumption that both twin types share similar environments but differ in genetic similarity. Higher concordance in monozygotic twins suggests genetic influence, while shared environmental factors are estimated from the excess similarity of dizygotic twins over that expected from genetic relatedness alone.
Usage
Usage note: Distinguish from adoption studies and family studies, which use different designs to study heritability.
In Context
- "The large-scale psychiatric twin study revealed substantial heritability for bipolar disorder across multiple populations." — psychiatric genetics research
- "Psychiatric twin studies provide crucial evidence for the genetic architecture of complex mental health traits." — behavioral genetics review