Schizophrenia - Biological explanations & treatments Flashcards
genetics, family studies, twin studies, adoption studies, other studies, neural - dopamine, brain structures, typical & atypical antipsychotics, evaluations
Genetics
Genes passed on through family
Family studies
Compare concordance rates between different degree relatives -> higher concordance rates = genetic basis
Twin studies
Compare concordance rates of monozygotic and dizygotic twins to find similar correlations
Adoption studies
Is environment or genetics the cause -> compare adopted children to their biological & adoptive parents
Candidates genes
Particular genes focused on to study development of features
Polygenic
Multiple genes involved
Aetiologically heterogenous
Different combinations of factors/genes lead to disorder
Lifetime risk of schz
1%
Genetic study: Riley & Kendler
First degree relative w/disorder -> 10x greater risk
Genetic study: Gottesman (family study)
2% blood aunt, 9% sibling, 48% identical twin
Genetic study: Tienari et al (adoption study)
7.5% when biological parents have schz, even if they grow up in adoptive family
Genetic study: Hilker et al (twin study)
33% identical, 7% non-identical
Genetic study: Ripke et al (candidate genes)
108 separate genetic variations associated with risk
Genetic counselling
Discussions about physiological & mental health and how it will impact individual’s family/children, understand their own genetics & family’s genes/risks
Other factors: Di Forti et al
Increased risk associated with high level THC smoking in teenagers
Other factors: Morgan et al
Complication during birth increase the risk
Other factors: Mokved et al
67% of their participants had at least 1 childhood trauma (compared to 38% in control group)
Dopamine hypothesis (original)
Hyperdopaminergia on subcortical level (higher levels of dopamine) -> increased positive symptoms
Dopamine hypothesis (updated)
Hypodopaminergia on cortical level (lower levels of dopamine) -> increased negative symptoms (+increased stress in early experiences -> more sensitive)
Studies on dopamine: Falkai
Schizophrenic patients post-mortem -> increased dopamine in left amygdala
Studies on dopamine: Tenn et al
Amphetamines induced schizophrenic-like symptoms in rats and reduced with other drugs
Drug use & psychosis
Abuse of opioids
- experience psychotic-like symptoms (hallucinations)
- increases release of dopamine
- deficiency of endorphins increases dopamine release & result in psychosis (withdrawal)
Other: Garson
Refutes ideas of drug-related psychosis imitating schizophrenia
Other: McCutcheon et al
Glutamate (responsible for learning, attention & memory) differs for each schizophrenic patient (candidate genes impact)