Schizophrenia- Biological Explanations Flashcards
What does the genetic explanation state?
States Sz is inherited and passed on from one generation to the next through genes, therefore a person’s born with genetic predisposition (likelihood) to Sz.
What does the genetic explanation believe?
Several maladaptive ‘candidate’ genes e.g. PCM1, are involved, increasing an individual’s vulnerability to developing Sz.
Studies show 108 separate genetic variations are associated with developing risk of Sz.
Gottesman (1991) Study
Studied 40 twins.
Found concordance rate for monozygotic twins was 48%.
found concordance rate for dizygotic twins was 17%.
The closer the genetic link to somebody with Sz, higher chance of developing Sz.
AO3: Genetic Theory
P: Research to support role of genetics in Sz development comes from Tierney.
E: Studied 155 adopted children, had biological mothers with Sz- concordance rate of 10%, compared to 1% in adopted children without schizophrenic parents.
E: Significantly supports role of genetics as explanation of Sz.
L: Role of Social Learning Theory couldn’t have been a factor as children were adopted.
AO1: Neural Correlates: Brain Structure/ Function
-A neural correlate is enlarged ventricles.
-Meta-analysis by Raz and Raz found majority of people tested with Sz had enlarged ventricles compared to control group.
-Enlarged ventricles associated with damage to central brain areas and pre-frontal cortex.
-Damage associated with negative symptoms of Sz.
AO3: Neural Correlates
P: Research to support role of neural correlates as Sz explanation comes from Suddath et al.
E: Used MRI scans to investigate brain structure of monozygotic twins, where one twin had Sz.
E: Found the twin with Sz generally had enlarged ventricles.
L: Suggests enlarged ventricles play a role in determining likelihood of developing Sz.
AO1: Neural Correlates: Dopamine Hypothesis
Brains chemical messengers appear to work differently in brain of patient with Sz.
Particularly, Dopamine’s widely believed to be involved as individuals with Sz may release too much dopamine/ have a large amount of D2 receptors on post synaptic neuron.
Hyperdopaminergia in the Subcortex
HIGH dopamine activity in central areas of brain e.g. Broca’s area may be associated with auditory hallucinations
Hypodopaminergia in the Cortex
LOW dopamine activity in prefrontal cortex are associated with negative symptoms of Sz e.g. avolition.
AO3: Biological Explanation of Sz: Strength: Scientific Methods
P: Used scientific methods.
E: Theory based on objective and empirical techniques e.g. gene mapping studies and brain scans e.g. fMRI, used to identify specific areas of the brain linked to Sz (e.g. enlarged ventricles).
E: Increases overall internal val of biological explanation of Sz.
L: Raising psychology’s scientific status.
AO3: Biological Explanation of Sz: Weakness: Biological Determinism
P: Criticised for biological determinism.
E: Theory states an individual’s controlled by internal factors e.g. hyperdopaminergia in the subcortex which inevitably causes auditory hallucinations.
E: Neglects the role of free will and choices individuals have, leaving victims feeling like they have no control over Sz behaviour.
L: Limits biological approach.
AO3: Biological Explanation of Sz: Strength: Practical Applications
P: Has practical applications.
E: Because principles of the theory (Sz caused by imbalance of dopamine) led to treatment of drug therapies e.g. typical/ atypical antipsychotics.
E: Drugs are effective in treating Sz by balancing dopamine levels in patients brain, reducing symptoms of Sz e.g. hallucinations.
L: Biological explanation’s an important part of applied psychology, helps treat people in real world.
