Define Heritability with an illustration
Heritability is proportion of variability in a trait that is due to genetic variations (genes passed from parent to offspring)
Illustration: Proportion of nature over proportion of nature plus nurture
Why should you be cautious when using heritability
Cautious to not assume that high heritability rules out any possible environmental influences
If variance in envrionment is low on average, heritability will always be recorded as high even if environment has significant impact on the conditon
Gene and environment interaction effects are rarely accounted for in research
Does schziophrenia and bipolar depression run in families
- Some studies argue up to 80% heritabillity
- First degree relatives have increased risk of both schizophrenia and bipolar depression.
BUT
Course of MI in families is disjointed - Family and twin studies show clear trends of the disorders running in families but genetic testing methods state heritability to be much lower (81 vs 23)
- Genetic testing involves identifying over 1000 genes with association with risk of schizophrenia
- then used genome ide single nucleotide polymorphisms (SNP) to form rleationship between psychiatric disorder and genes
- SChizophrenia and bipolar share 16% of common genetic variation
BUT genome testing is subject to the base rate problem (Suffers in statistical significance)
Overall, genetic risk is smaller of the 2 influences
What social factors are associated with psychosis
Social
- Interpersonal trauma and early adversity (bullying, parental death, trauma)
- studies show that 33% of people would not have become psychotic had the risk factor (Early adversity) not been present, this adds up to 80,000 people in Canada
- 2007 study found specific trauma linked to specific symptoms : Rape and hallucinations, neglect and paranoia
Adverse social conditions affect psychological mechanisms that lead the victim toward psychosis
What environmental factors are associated with psychosis
Environmental
Cities: Found a positiver correlation for admissions for psychosis and urbanicity but it wasn’t statistically significant
- Stronger colleration for social deprivation and fragmentation with first admissions for psychosis
- High income inequality countries found to have higher psychosis rates, along with other negative factors like crime rate
- Low percieved social status also associated with high prevalence of MD (true for every country. 1.4-4.9 odds ratio
Migration: Ethnic density effect: psychosis more common for people in some ethnic groups in areas where their ethnic group is less common.
What are ACEs?
Adverse childhood experiences, potentially traumatic events that can have lasting negative effects on the health and well being of the child. Range from physical to emotional and sexual abuse to parental divorce/ incarceration
- 1988 research on psychiatric patients outlined 7 distnict types to be operationalised in studies (Health risk factors etc.)
- Study found that over half had at least 1 exposure, quarter had 2 or more
How have ACEs been used to describe causes of psychological harm to children as adults
ACEs used to describe causes of psychological harm by researchers finding positive correlation between ACEs and people in psychiatric facilities as well as risk for disorders like depression, ptsd etc.
ERISK study
used ACEs to describe causes of psychological by conducting a longtiduinal study
on children to prospectively measure ACEs and test if these measures could predict mental and physical health problems occurring later in young adulthood
Outcomes: mental health had 1.14 higher risk per each additional ACE
- But ACE had poor accuracy in predicting an individuals risk of later health problems
Describe the possible physical consequences of ACEs
- Morbid obesity
- Physical inacitivty
- Heart disease
- Stroke
- STIs
- Diabteres
Chronic obstructive pulmonary disease
Hepatitis
ERISK study - outlines physical health risks such as ASthma, sleep problems, and high CRP
Brain development –> GLobal volumetric changes in brain - Emotional neglect/ physical abuse lead to smaller amygdala
Prefrontal cortex and cerebllum changes associated with maltreatment related PTSD
2015 study found significant odds ratios for those with ACEs and type 2 diabetes
CVD has linear trend with number of ACEs
Premature mortality associated with ACE scores of above 6 (average 20 years earlier)
What kind of dissociative disroder was experience by Jenny in the last truth, What evidence is there to support
Jenny experiences type of derealization/ depersonalisation disorder
DEatchment from one’s feelings, sensations adn body or detatchment to surroundings, objects are unreal or foggy
- Likely a result of PTSD she experiences due to childhood sexual abuse
Evidence:
- Tended to show symptoms of disassotiation during sex/ any procedure involving her genitals
- Described to emerge from a distance place after sex with mark and be absent often during sex
- Dr Jay saw a flaccid masked expression as if she were unconscious while examining her vagina
- She used to dissasociate while facing sexual abuse as a child (Was seen by tad to have no expression on her face when he saw her in her mothers bed)
