Background - The Medical Model

Cause - Believes mental illness is due to imbalance of chemicals within our bodies.

• However, hard to establish cause and effect 

• Serotonin → links with depression, low levels means messages are passed ineffectively through neutral pathways = lower moods e.g. depression 
• Dopamine → excess dopamine has associations with schizophrenia as a result of an overactive dopamine system
• Anxiety → linked with biochemicals such as serotionin and norepinephirine

Cause - Believes that some disorders are assed through genetic → evidence through reseach of monoygotic and dizygotic twins 

• If identical twins are separated but both have the same disorders, it could be conluded that this is due to genes

Gottesman & Sheilds (1976) → researched adapotion and twin samples

• Found increased concordiance rates but never 100% with 58% concordance rate for monozygotic twins

Cause - Believes that the size and weight of the brain can influence a person's mental illness.

• Brown et al → studied 41 schizophrenic's brains & 29 brains of people with affective disorder.
  • Those with schizophrenia brain's were 6% lighter and larger temporal horn section.
• Weinberger (1992) → looked at identical twins
  • Found differeces in brain structures, in particular prefrontal cortex
• Strakowski et al (1999) → found that patients with bipolar disorders had significant differences in volume of prefrontal and amygdala

Brain Volume 

• Patients suffering from deression have smaller hippocampal volume than non-depressed people