Higher adiposity and mental health: causal inference using Mendelian randomization
Francesco Casanova1, Jessica O'Loughlin1, Susan Martin1
1Genetics of Complex Traits, The College of Medicine and Health, RD&E Hospital, University of Exeter, Exeter EX2 5DW, UK.
Human Molecular Genetics
|July 16, 2021
Summary
Higher body mass index (BMI) is causally linked to increased depression risk and lower well-being. This genetic study suggests adiposity impacts mental health, even without metabolic issues.
Area of Science:
- Psychiatry and Genetics
- Metabolic Health and Mental Well-being
Background:
- Higher adiposity is a known risk factor for psychiatric conditions like depression and anxiety.
- The link between adiposity and depression may stem from metabolic changes or psychosocial factors.
- Understanding the causal relationship is crucial for public health interventions.
Purpose of the Study:
- To investigate the causal effect of higher adiposity on mental health and well-being outcomes.
- To differentiate between metabolic and psychosocial influences of adiposity on mental health.
- To utilize Mendelian randomization to establish causality.
Main Methods:
- Employed one- and two-sample Mendelian randomization (MR) in a large European cohort (UK Biobank).
- Utilized three sets of genetic instruments for adiposity: BMI variants, favorable adiposity variants, and unfavorable adiposity variants.
- Analyzed 10 mental health and well-being outcomes from the Mental Health Questionnaire (MHQ).
- Conducted subgroup analyses (sex-specific, non-antidepressant users) and non-linear MR.
Main Results:
- Genetically predicted higher BMI (1-SD increase) was associated with increased odds of current depression (OR: 1.50) and lower well-being (ß: -0.15).
- Results were consistent across different adiposity genetic instruments, including metabolically favorable and unfavorable variants.
- Higher adiposity showed a causal association with increased depression risk and reduced well-being, independent of metabolic effects.
Conclusions:
- Higher adiposity causally increases the risk of depression and lowers well-being.
- The study suggests that adiposity's impact on mental health persists even when adverse metabolic consequences are absent.
- Findings reinforce the importance of managing adiposity for mental health outcomes.
Related Concept Videos
01:28Human Genetics
917
Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
The complex relationship between genetics and psychology is observable through common biological components such...
917
01:52Regression Toward the Mean
6.6K
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...
6.6K
01:53Cause and Effect
11.6K
While variables are sometimes correlated because one does cause the other, it could also be that some other factor, a confounding variable, is actually causing the systematic movement in our variables of interest. For instance, as sales in ice cream increase, so does the overall rate of crime. Is it possible that indulging in your favorite flavor of ice cream could send you on a crime spree? Or, after committing crime do you think you might decide to treat yourself to a cone?
11.6K
01:30Stress and Mental Health
279
Chronic stress profoundly affects mental health, significantly influencing mood, behavior, and overall quality of life. Research closely links chronic stress with mental health conditions such as depression, anxiety, and substance use disorders. Ongoing exposure to stress can lead to physiological and psychological changes, initiating a cycle of emotional distress and maladaptive coping mechanisms.
Individuals with depression often experience challenges in both their personal and professional...
Individuals with depression often experience challenges in both their personal and professional...
279
01:21Causality in Epidemiology
1.1K
Causality or causation is a fundamental concept in epidemiology, vital for understanding the relationships between various factors and health outcomes. Despite its importance, there's no single, universally accepted definition of causality within the discipline. Drawing from a systematic review, causality in epidemiology encompasses several definitions, including production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic models. Each has its strengths and...
1.1K
01:29Bias in Epidemiological Studies
858
Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:
858