The Biological model of abnormality

The Biological model of abnormality

Medical model -->Mainly used by psychiatrists
Most widely accsepted model

Assumptions
1)abrnomality is inherrited
2)all behaviour is a product of processes in the brain and body; e.g- hormones, nervous system, genetics
3)adnormal behaviour is a process gone wrong

unwanted behaviours can be treated using biological methods, eg; drugs.

The Biological model of abnormality

Methods of investigation
-Blood tests
-MRI's
-PET's

Infections
-Syphylis bacterium; general paresis. now treated

-Herpes Simplex Virus; can damage brain.   EX; Clive Wearing

-Torrey 2001; women with particular strain of flu whilst pregnant-->children more likley schiz'nic

The Biological model of abnormality

NEUROTRANSMITTERS
-Too much or too little
For example; to much dopamine is linked to schizophrenia + different membrane structure of neurones (lower levels of fatty acids)

The Biological model of abnormality; Brain injury.
BRIAN INJURY
1)Physical injury  - Phineas Gage; railroad construction foreman US, preparing for explosion using tampering iron, iron produced spark, igniting powder, resulting in blast which prepelled iron rod through head.
before injury --> effiecient and capable  
after injury-->fitfull, irrelevent, indulging, impaintent and resistant
described as 'no longer Gage'

2) Brain tumour - Charles Whitman
-murdered wife + 14 others + self.     suiside note asked for autopsy  small tumour found.     was this the cause for his behaviour?

3)Brain damage due to stroke
-blood supply to part of brain interupted
-results depend on which area of brain affected

The Biological model of abnormality
GENETIC EXPLANATIONS OF ABNORMALITY
-Certain genes --> abnormal neuronatomy 
           eg; large ventricals (brain tissues shrunk) assosiated with sciz'nia

-genes determine seretonin or hormone levels
          -high levels->anxious             low levels->depressed

defect in a single gene is enough to cause a problem if both parents carry a faulty gene and child gets a copy from both parents.

EG; PKU child with faulty gene cant convert phenyalanite (in food) into melanin. build up of phenyalanite can cause brain damage.
-->heal ***** test done on all newborns. if found food with phenlyaline must be avoided.