Week 2 - Models of Psychopathology Flashcards
The Scientist-Practitioner Approach
Psychologists use research findings to guide assessment, dialogue treatment of people with mental health disorders
- Empirically supported assessment & treatment strategies
What are models used to explain?
Models are used to explain:
- Origins of abnormal behaviour
- How to treat it
- How to prevent it
They provide a representation of the real world
Research tests hypothesises derived from models
Biological Models
Aetiological models: * Genetics * Biochemistry
* Neuroanatomy
* Endocrine system
Genetics: Studies of gene-environment interactions
1. The pedigree method
2. Classical twin design
3. Adoption studies
4. Molecular genetics
The Pedigree Method
Biological Model - Proband Identified
Tracking within a particular family across the generations if there is a heritable disorder
Natural Vs Nurture
Environment is important to be taken into account as well
The Classical Twin Design
- Compares concordance rates for Monozygotic (MZ) and Dizygotic (DZ) twins. * Differ in genetic similarity, but likely not different environmental experiences
- If MZ > DZ: genetic contributions * If MZ = DZ and both show high concordance; shared environmental contributions
- E.g., growing up in poverty
- If MZ = DZ, and both show low concordance; non-shared environment contributions
- E.g., Experiences unique to one twin
Adoption Studies
- Compares the concordance of a disorder in adopted children: * To their biological relatives
- To their adoptive relatives
Molecular Genetics
Genetic Association Studies
Candidate gene studies
- Is one allele more frequently seen in people with the disorder than in people without the disorder?
ApoE-e4: 37 with Alzeimers disease vs 14% in general population,
Genome wide association studies
- Assess common variation across the entire genome
No single gene has been found to be entirely responsible disorders
Biochemsity as Aetiology
- The anatomic structure of the neuron, or nerve cell:
Biochemsity as Aetiology
- The anatomic structure of the neuron, or nerve cell:
Synaptic Transmission
Neurotransmitters: Chemicals released into the synapse
between two neurons that carry signals from the terminal of one
neuron to the receptors of another
How the synaptic transmission effects the abnormal psychological disorder
Biochemistry as Aetiology
Most druge therapies increase or decrease the activity of specific neurotransmitter systems have very broad effects
BUT: Neurotransmitter systems have very broad effects
The four neurotransmitter systems
There are four that are important to take into account when focusing on modelling for biological disorders
- Serotonin
Regulates behaviour, mood & thought processes
- Low seratonin actiity associated with
- Aggression, Suicide, Impulsive overeating, Hyper-sexual behaviour
Drugs that primarily affect the seratonin system
- Tricuclic antidepressants
- Seratonin specific reuptake inhibitors (e.g Prozac)
Gamma Aminobutyric Acid
- Inhibits a variety of behaviour & emotions
Seems to reduce arousal, anxiolytic effects
Benzodiazpines make it easier for GABA molecules to attach themselves to the receptors of specialized neurons
Noradrenalin
Secreted by adrenal glands
Noradrenalin circuits in CNS:
1. Hindbrain, in an area that consols basic bodily functions such as respiration
2. Another circuit influences the emergency reaction that occur when we suddenly find ourselves in a very dangerous situation
Dopamine
Dopamine circuits merge and cross with seratonin circuits - influence many of the same behaviour
Relays messages to control movements, mood and thought processes
Parkinson’s disease: dopamine-producing cells damaged
Hindbrain
Function involved in sustaining life, regulation of sleep
Midbrain
Regulation of some motor activies (fighting & sex) and sleep
Forebrain
Site of most sensory, emotional & cognitive functioning
Limbic system
Links to the forebrain with the midbrain with and the hindbrain
Regulate emotion and learning
Make note: Specific disturbances may result from damage to specific areas of the brain
.