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A New Method for Inducing a Depression-Like Behavior in Rats
Published on: February 22, 2018
Major depression and life satisfaction: a population-based twin study.
Ragnhild B Nes1, Nikolai O Czajkowski, Espen Røysamb
1Division of Mental Health, The Norwegian Institute of Public Health, Oslo, Norway. Ragnhild.bang.nes@fhi.no
Journal of Affective Disorders
|October 2, 2012
Summary
Genetic factors significantly influence both Major Depressive Disorder (MDD) and life satisfaction (LS), while environmental factors appear distinct for each. This suggests shared genetic vulnerability but separate environmental pathways for MDD and LS.
Area of Science:
- Psychiatry
- Behavioral Genetics
- Mental Health Research
Background:
- Limited research exists on shared etiological influences between positive and negative mental health indicators.
- This study investigates the genetic and environmental underpinnings of the association between Major Depressive Disorder (MDD) and dispositional life satisfaction (LS).
Purpose of the Study:
- To examine the genetic and environmental influences on the association between liability to lifetime Major Depressive Disorder (MDD) and dispositional life satisfaction (LS).
Main Methods:
- Utilized two-wave questionnaire data on LS (6-year interval) and lifetime MDD from structured clinical interviews.
- Analyzed data from a population-based sample of adult twins using structural equation modeling in Mx.
Main Results:
- Prevalence of lifetime MDD was 11.1% in males and 15.8% in females.
- Individuals with MDD reported significantly lower LS.
- Phenotypic correlation between MDD and LS was 0.36, with 74% attributed to genetic influences and 26% to unique environmental factors.
- Heritability estimates were 0.34 for MDD and 0.72 for LS.
Conclusions:
- Genetic factors substantially contribute to the shared liability between MDD and low LS.
- Environmental influences on MDD risk and LS appear distinct, suggesting they do not strongly impact each other.
- Twin study design has inherent limitations.
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