Exam lecture 1: Complexity
Dream theory - Sigmund Freud (1917)
One component: If we dream about vegetables, then these are relatively often in the shape
of cucumbers or carrots (sexually associated shapes). But this is actually not the case,
because the top 3 vegetables in dreams are potatoes, tomatoes and onions, this is probably
because these are the most eaten vegetables in the world.
→ This is a scientific explanation of observations of (distorted) behavior and thought, which
will be explained during these 3 lectures ‘complexity’, ‘severity’, ‘capacity’
Attachment is associated with mental health.
People who have a less secure attachment are
more likely to have an illness such as depression.
But in between this attachment variable and mental
health there’s a ‘big black box’ where something
changes in your brain or changes something on the
content of your brain, but what exactly happens is
still vague.
All these variables are associated with mental
health and in the end it’s the interaction of all these
variables that define the outcome and not just a
simple variance as attachment.
Example to show that the science on risk factors is way more complex than you may expect:
The risk of psychosis. This risk is present from fetal life until adulthood.
Psychosis = A symptom (hallucinations and/or delusions, aka positive symptoms)
Schizophrenia = A syndrome (positive and negative symptoms, a.o. loss of motivation)
The large part of your risk of becoming psychotic in your life is defined by the genes of your
parents, you get ‘risk’ from your mother and ‘risk’ from your father. But in the end, there are
no specific genes for psychosis, drug-dependence or depression.
Amino acids → proteins → protein complex → cell structure / function → behavior
So: There’s a long way from the genes you get from your parents to behavior.
Rule of thumb: If the prevalence of a disorder is high, then the genetic component usually is
not that large.
Example: Girl with rat syndrome. The heritability estimate is 1 because it’s a single mutation
that enters your gene that takes place on the X-chromosome (more likely that girls get it).
This is an one-on-one relation, but most of the time an one-on-one relation is NOT the case.
Older parents (> 35 years) have a higher risk of giving birth to a child who will experience
psychosis.
Two hypotheses for paternal age and psychosis risk:
- The de novo mutation hypothesis
- The selection into late fatherhood hypothesis
, De novo mutation hypothesis
This hypothesis says that older fathers have more mutations
on their genes, which can lead to distorted behavior. When
males age, more mutations will take place and these mutations
will end up in the germline and in the end in the sperm. A
mutation is a potential error in the blueprint.
(Mutations are also the driving force underlying evolution.)
Selection into late fatherhood hypothesis
The increased risk is due to other correlates of late fatherhood (e.g. old father perhaps are ..
different in ...). Due to certain correlates they might be a bit ‘weird’ and that’s why they did
not succeed in finding a mate at a younger age. Perhaps these fathers do not create an
environment for their children that is optimal. In case there is a suboptimal nurture
environment, the odds of for example, drug use increase largely over the years for the child.
In a study looking at drug use, you see that if the use increases, also the odds on psychosis
increases. This looks simple: If you would reduce the use of cannabis to zero (no use), then
the prevalence of psychotic symptoms would reduce by half. But what we actually see is that
the most unhealthy category but also the most healthy category have the highest risk, this is
probably because they’re very strict or very harsh in their nurture environment.
Cannabis use is a trigger for psychosis risk for
some, but not for all. The risk of psychotic behavior
as a function of cannabis use shows two different
results. What’s the case, is that there is a gene
variance that is perhaps associated with synaptic
plasticity and with immune functioning which
perhaps could explain why cannabis use can lead
to a higher risk in some people than others.
→ This is de gene-environment interaction (G x E)
But it can also be the case that there’s no causal relation of cannabis use on psychosis risk,
alternatives:
- Self-medication hypothesis: People who with (early signs of) the illness take
cannabis to cope with it
- Just a correlation: Genes that make prone to psychosis also make prone to cannabis
use; G-E correlation
Social causation and social selection / drift
Socio-economic status (SES) is a very important factor when it comes to health.
- The social causation hypothesis: Adverse social-economic conditions increase risk
on poor mental health, psychosis included.
- The social selection/drift hypothesis: People ‘drift’ into adverse social-economic
conditions because of poor mental health, psychosis included.
For example, if you become psychotic, depressed or dependent on alcohol, you can’t
follow your study anymore or your career can’t flourish, this will in the end add up to a
lower social status.
→ These hypotheses are not mutually exclusive, they can even exist alongside each other.