L1: Evolution and development of health behaviour

Question 1

evolution and depression paradox

Answer 1

why did natural selection not eliminate depression from the population?

Question 2

lifetime prevalence of depression in NL

Answer 2

18%

Question 3

heritability of depression

Answer 3

40%

Question 4

Genome-wide Association Study about depression

Answer 4

No SNPs achieved significance

Question 5

fecundity =

Answer 5

fertility

Question 6

resultaten van studie over fertility bij mental disorders

Answer 6

Except for women with depression, affected patients had significantly fewer children. But males did have significantly fewer children.

Dus waarom niet bij depressie?

Vulnerability to depression, and perhaps substance abuse, may be preserved by balancing selection, suggesting the involvement of common genetic variants in ways that depend on other genes and on environment.

Question 7

balancing selection=

Answer 7

Balancing selection is an evolutionary process that maintains genetic diversity within a population by favoring the persistence of multiple alleles (gene variants) at a specific locus. Instead of driving one allele to fixation (where only one variant remains), balancing selection helps keep different alleles in the gene pool. It plays a crucial role in maintaining genetic variation, which can be beneficial for a population’s ability to adapt to changing environments.

Question 8

why do humans get depressed?

Answer 8

• cry for help
• reaction to losses
• seasonal (no activity in winter)
• energy conservation
• rumination, solving problems
• association with inflammation/infections
• mismatch

Question 9

relatie inflammation and depression

Answer 9

Crosstalk between inflammatory pathways and neurocircuits in the brain can lead to behavioural responses, such as avoidance and alarm, that are likely to have provided early humans with an evolutionary advantage in their interactions with pathogens and predators. However, in modern times, such interactions between inflammation and the brain appear to drive the development of depression and may contribute to non-responsiveness to current antidepressant therapies. Recent data have elucidated the mechanisms by which the innate and adaptive immune systems interact with neurotransmitters and neurocircuits to influence the risk for depression.

evolutionairy pressure (conspecifics, predators, pathogens) -> inflammatory bias -> alarm, avoidance in the brain & wound healing, fighting infection in cells -> more infectious mortality, less inflammtory conditions and less autoimmunity & immunoregulatory system upregulated -> less infectious mortality, more inflammatory conditions and more autoimmunity & environmental, social and medical stress -> depression

Question 10

kijken naar unified model of depression in schrift

Answer 10

oke

Question 11

mismatch hypothesis=

Answer 11

we are not adapted to modern environments, but to ancestral environments. this results in a mismatch

Question 12

what was the environment of evolutionary adaptedness

Answer 12

• savannah-like environment
• hunter-gatherer society
• nomadic lifestyle
• physical dangers
• high infant mortality
• food scarcity

Question 13

mismatches we currently have:

Answer 13

• diet
• physical activity
• childrearing
• sunlight
• sleep
• social interactions

Question 14

Hadza =

Answer 14

protected hunter-gatherer tribe in tanzania

Question 15

evidence for mismatch hypothesis

Answer 15

1. developing countries have less mismatches regarding mood disorders than rich countries
2. rural areas have less mismatch than urban areas
3. more mismatch in modern societies than traditional societies
4. more physical activity is less mismatch, less physical activity is more mismatch
5. more mismatches is more depression, less mismatches is less depression

Question 16

diseases that occur more in urban areas

Answer 16

• depression
• anxiety
• diabetes
• hypertension
• asthma
• copd

Question 17

association between urbanization and depression is confounded by…

Answer 17

• poverty
• immigration
• availability of green spaces in the city

Question 18

more mismatch in modern societies than mismatch societies: voorbeelden

Answer 18

• nothing like depression in Kaluli, a hunter-gatherer society in new guinea
• more depression after modernization in china

Question 19

physical activity patterns and biomarkers of cardiovascular disease risk in hunter-gatherers

Answer 19

Time spent in moderate-to-vigorous physical activity (MVPA) is a strong predictor of cardiovascular health, yet few humans living in industrialized societies meet current recommendations (150 min/week). Researchers have long suggested that human physiological requirements for aerobic exercise reflect an evolutionary shift to a hunting and gathering foraging strategy, and a recent transition to more sedentary lifestyles likely represents a mismatch with our past in terms of physical activity. The goal of this study is to explore this mismatch by characterizing MVPA and cardiovascular health in the Hadza, a modern hunting and gathering population living in Northern Tanzania.

These results provide evidence that the hunting and gathering foraging strategy involves high levels of physical activity, supporting the evolutionary medicine model for the relationship between physical activity and cardiovascular health.

Question 20

results physical activity and depression

Answer 20

Depressive symptoms decrease with more physical activity; moderate exercise and high intensity both work

Question 21

mismatch questionnaire is based on these factors:

Answer 21

• Deviant sleep rhythm
• Lack of exercise
• Processed food
• Lack of daylight / being outside / green environment
• Lack of contact with family, friends, partner
• Materialism
  -Perfectionism / focus on achievement
   Lack of time
   Worrying (deadlines, finances, job
  security, climate change)
   Lack of freedom
   Lack of joy (dancing, singing)
   Social media addiction
   Deviant youth (no siblings,
  breastfeeding, warmth)
   Unhealthy habits (smoking,
  alcohol, drugs, coffee, medicines)

Question 22

correlations between depression and sensitivity and mismatch factors

Answer 22

correlation depression and mismatch factors
controlling for sensitivity:
r(103) = .38, p < .001 (without controlling: .50)
correlation sensitivity and depression
controlling for mismatch factors:
r(103) = .22, p < .025 (without controlling: .37)

Question 23

best predictors of depression:

Answer 23

• Lack of freedom
• Lack of time
• Worrying
• Processed food
• Sleep rhythm
• Perfectionism
• sensitivity is a moderator

Question 24

oplossing voor deze mismatches:

Answer 24

• less grains and dairy
• raw foods (less processed foods)
• calorie restriction
• intermittend fasting
• barefoot running
• more exercise/weight training
• better sleep rhythm
• more music/singing/dancing
• greener environment
• more sunlight
• less social media
• less shopping
• more close interactions (tribe)
• less individualism
• less perfectionism
• less worrying

Question 25

mindfulness/meditation

Answer 25

Non-judgmental and accepting awareness of the present moment
- Jon Kabat-Zinn
- Mindfulness-Based Stress Reduction

Question 26

results of mindfulness study

Answer 26

• mindfulness improves symptoms of all kinds of disorders
• prevents depressive relapse