Lecture 6-Biomedical Model Flashcards
What are used to explain phenomenas in science?
Models (paradigms)
What do models do?
Spell out assumptions, give order to the field and give structured framework for investigation
What do models influence?
What investigators observe, the questions they ask, the infromation they seek and how they interpret data
How do research findings interpreted?
In the context of existing scientific models
What perspective is the bio model of mental disorders?
Medical and bio perspectives
What are the assumptions of the bio model?
Mental disorders are biologically based brain diseases
The cause is structural and physical
Mental disorders reflect something wrong with the brain structure or function
What is the aim of research for the biological model?
To uncover the bio cause of mental disorder
What is the emphasis of the bio model?
On medical treatment
What does the bio model argue?
There is no distinction between mental and physical diseases
What is maladaptive behaviour considered to be?
A function of interaction between biological, psychological and social factors
What has the bio model caused an increase of?
Use of pharmalogical agents in mental illnesses
What do PET scans show in depression?
Reduced brain activity in depression
What are the biological causes of mental disorders?
Neurotransmitters and hormones
Genetics
Developmental abnormalities
Physical deprivation, neglect or stress
Toxic agents
What are the three neurotransmitter imbalances?
Altered production, altered reuptake and alternations in neurotransmitter receptors
What is altered production?
Altered production of neurotransmitter at synapses, over or under-stimulating the target neuron
What is altered reuptake?
Altered reuptake of neurotransmitters, increasing or decreasing concentration at synapses
What is alternations in neurotransmitter receptors?
Alterations in neurotransmitter
receptors, so that they are abnormally sensitive or insensitive
Who looked at hormones?
Carlson, 2007
What did Carlson, 2007, find?
Dopamine, norepinephrine, serotonin, glutamate and GABA has been studied in relation to psychpathology
What are the 2 types of psychotropic drugs?
Agonist and antagonist
What are agonist drugs?
Drugs that increase neurotransmitters binding to receptors
What are antagonist drugs?
Drugs that decrease neurotransmitters binding to receptors
What do psychotropic drug increase?
Synaptic transmission
What are the psychotropic drug mechanisms?
Increase or decreased synthesis, increase or decrease transmitter re-uptake and direct stimulation or inhibition of transmitter receptors
What does drug discovery allow?
Sheds light on mechanisms of disease or understanding disease mechanisms allows rational drug design
What does resperpine do?
Treat high blood pressure but then caused depression and depletes nerve cells of amine neurotransmitters
What does iproniazid do?
Was an anti-tuberculosis drug and caused euphorbia, increased appetite and improved sleep as it increased amine neurotransmitters
What is depression caused by?
Deficiency of amine neurotransmitters
How do anti-depressants work?
Correct amine brain levels
What do SSRIs do?
Block the re-uptake of serotonin such as sertraline
What are criticism of amine hypothesis?
There are inconsistent findings
Poor control of confounding variables
Used small sample sizes
An oversimplification
Based theory on disease causation
What is the amine hypothesis of schizophrenia?
Excess of dopamine causing delusions and hallucination
What is the amine hypothesis of OCD?
Symptoms due to dysfunctions of brain pathways regulated by serotonin
What are the problems of bio models of disease?
Simplistic and misleading
What are characteristics of bio disease models?
Complex and suppirted by extensive research evidence such as animal models, autopsy, fMRIs and genetics
What is the endocrine system?
System of glands that secrete hormones in the bloodstream
What are hormones?
Chemical messengers that control body functions
What is the main gland?
Pituitary
What is the pituitary controlled by?
Hypothalamus
What can over activity in stress states cause?
Chronic psychological stress for elevation of cortisol (leads to depression + anxiety)
What are the genetic vulnerabilities?
Chromosomal abnormalities and single gene defects
Who looked at genetic vulnerabilities?
Ploemin et al
What did Ploemin et al find?
There is evidence that disorders have genetic influence
What are chromosomal abnormalities?
Complete or partial duplications/deletions
What are single gene defect?
Abnormalities in particular genes or disease associated normal variants
What does polygenic mean?
Vulnerabilities to mental disorders
Who looked at polygeny?
Kendler, 2005
What did Kendler, 2005, find?
Disorders are influenced by multiple genes causing genetic vulnerability
What is epigenetics?
Genes being switched on and off