Biological Explanations

Question 1

Genetic Explanation

Answer 1

Schizophrenia runs in families. Gottesman et al (1991) conducted large scale family study and found genetic similarity increased, so does probability of sharing schizophrenia (1% likelihood of population, but 48% if identical twin has it). Polygenic and aetiologically heterogeneous. 108 genetic variations (Ripke). These genes are associated with coding for dopamine.

Question 2

Neural Correlates

Answer 2

Variations in activity of brain that are correlated with an increased risk of developing schizophrenia. Juckel et al (2006) lower activity in ventral striatum (associated with anticipation of reward) linked to negative symptom of avolition. Allen et al (2007) lower activity in superior temporal gyrus (associated with auditory processing) and anterior cingulate gyrus (involved with emotion and behaviour) linked to positive symptoms of hallucinations, especially auditory.

Question 3

Dopamine Hypothesis

Answer 3

Dopamine is a neurotransmitter associated with mood balancing and regulating emotions. Excess of dopamine receptors leads to high levels of dopamine activity producing excitation response in Broca’s area associated with speech poverty and auditory hallucinations. (hyperdopaminergic) Goldman-Rikt et al (2004) low levels of dopamine receptors in prefrontal cortex responsible for thinking and decision making cause abnormalities to this, associated with avolition and speech poverty. (hypodopaminergic)

Question 4

Strength 1 (genetic)

Answer 4

Supportive evidence from Gottesman et al (1991). However, identical twin concordance rates aren’t 100%. Furthermore, shared environment inflate statistics, However, Tiernari et al (2004) did show heightened risk if parents had it.

Question 5

Strength 2 (neural)

Answer 5

Research support from Juckel et al (2006). However, correlational, but best we got, so used with caution

Question 6

Strength 3 (DH)

Answer 6

Supportive evidence from Leueht et al showing effectiveness of antipsychotics compared to placebos, however, reduce symptoms but may not address cause, however, do still better quality so useful.

Question 7

Weakness (all)

Answer 7

Reductionist, diathesis stress model