What is a Paradigm
Paradigms in the Study of Mental
Disorders
Etiology
the cause or origin of a disease
Symptomatology
the study of, or the treatment of, the
symptoms of a disease
Biological Paradigm
Mental disorders caused by aberrant or
defective biological processes
what does the biological paradigm focus on
Focuses on
* Genetic Heritability
* Neurochemical Communication
* Brain Structure
Focus on interaction between organic functioning
(genetics, physiological & neurological systems) and
behaviour (normal & abnormal).
Genotype
unobservable genetic constitution
* The total genetic makeup of an individual
* Fixed at birth, but it should not be viewed as a static entity
Phenotype
totality of observable, behavioural
characteristics
* Dynamic (i.e., it changes over time)
* Product of an interaction between genotype and environment
Family method
Can be used to study a genetic
predisposition among members of a
family b/c the average number of
genes shared by two blood relatives is
known
* Index cases, or probands
* Individuals who bear the diagnosis in
question.
Twin method
adoptees method
In the adoptees’ study method, researchers identify proband birth parents with a certain characteristic (e.g., alcoholism) and then examine the outcome of these probands’ adopted-away children.
Molecular genetic studies identify:
which genes are involved
in behavioural disorders
Linkage analysis
uses genetic markers as a clue in locating
genes controlling disorders
Genetic Marker
a gene for which we know the location and
function.
* Genes have a tendency to be passed along in clusters, so if we can
find some characteristic that is generally inherited along with the
disorder (and if we know the gene location for that characteristic),
then we can look at nearby genes to find a gene for the disorder.10
Molecular Genetics: Method
Frontotemporal Dementia (FTD):
The second most common type of dementia other
than Alzheimer’s disease
Epigenetics
heritable changes in gene activity that are
caused by environmental experience
Dias & Ressler (2014)
Each neuron has four major parts:
Nerve impulse
A change in the electric potential of the cell that
travels down the axon to the terminal endings
Synapse and neurotransmitters
Chemical substances that allow a nerve impulse
to cross the synapse.
Mental Disorder in regards to synapse
Imbalance in levels of
one or more
neurotransmitters
* Receptors are the issue
Neurotransmitters & Abnormal Behaviour
Abnormal behaviour can result from disturbances in
neurotransmitter systems in various ways:
* Too much/little of the neurotransmitter produced or released
* Too few/many receptors on the dendrites
* Excess/deficit of the transmitter-deactivating substance in
the synapse
* Reuptake process may be too rapid/slow
* In addition, the effects may change depending on the
location of the disturbance
Biological Approaches to Treatment of mental disorders
Prevention or treatment of mental disorders should
be possible by altering bodily functioning
* Psychoactive medications
* Deep brain stimulation
Behavioral Paradigm: Learning