Psychopathology - OCD Flashcards
what does the biological approach assume for the explanation of OCD?
assumes that OCDs are caused by physiological factors such as brain chemistry, neuroanatomy and genetics
what is the genetic explanation of OCD?
- genetic evidence has found that first degree relatives of people with OCD have a greater vulnerability of developing the disorder
-Nedstadt et al found that first degree relatives of OCD sufferers had a 3% chance of developing the disorder compared to a 12% risk in the general population
Hence the genetic explanation suggests that some people may inherit a genetic predisposition to developing OCD
-in summary, the genetic explanation suggests that some people may inherit a genetic predisposition to developing an OCD
What is the one of the genes that could be responsible for OCD? - starts with an S
-(for genetic explanation of OCD)
-research has found a specific type of gene that could be responsible for OCD called candidate genes. These genes are involved in regulating the production of the neurotransmitter serotonin which correlated with cases of OCD
-one such impaired gene is called the sert gene. If this is impaired, it leads to problems with the transport of the neurotransmitter serotonin. This ultimately leads to diminished levels of serotonin which correlates with cases of OCD
-in one study a mutation of this gene was found in 2 unrelated families where 6 out of 7 members has an OCD
What is another gene that may be responsible for OCD?
-starts with a D
(for the genetic explanation of OCD)
-another candidate gene identified in cases of OCD is an impaired COMT gene. In short, this gene regulates the production of another neurotransmitter called dopamine. An impaired COMT gene leaves too much dopamine in the synapse, resulting in some of the compulsive behaviors seen in patients with OCD.
-Taylor has identified up to 230 candidate genes that may contribute to OCD, which ultimately suggests that OCD is polygenic
what are the strengths of the genetic explanation for OCD?
-evidence to support
-promotes psychology as a scientific discipline
what are the weaknesses of the genetic explanation for OCD?
-research also demonstrates that genes cannot be the only factor in the development of OCD
-can be considered biologically reductionist
what is the neural explanation of OCD?
-that the role of a damaged caudate nucleus and the orbitofrontal cortex
-several layers of the front lobes of the brain are thought to be abnormal in people with OCD. the caudate nucleus normally suppresses signals from the orbital frontal cortex (OFC)
-in turn, the OFC sends signals to the thalamus about things that are worrying, such as a potential germ hazard. when the caudate nucleus is damaged, it fails to suppress minor ‘worry’ signals and the thalamus is alerted, which it turn sends signals back to the OFC, acting as a worry circuit.
What is the role of low serotonin (for neural explanation of OCD)
-lower levels of the neurotransmitter serotonin which influences mood regulation, anxiety, sleep and social behavior has been linked to OCD
-the exact influence of lowered levels of serotonin plays a role in preventing behavior repetition and therefore low levels of this neurotransmitter may be linked to the compulsions that can be displayed as a symptom of OCD
What is the role of low dopamine for the neural explanation of OCD??
- lower levels of dopamine have been linked to OCD
- dopamine is released when your brain is expecting a reward. When you come to associate a certain activity with pleasure, mere anticipation may be enough to raise dopamine levels
- it could be certain food, sex, shopping or anything you enjoy
- but when you don’t get that feeling of a reward your brain has to do it over and over to feel it
What are the strengths of the neural explanation??
- research support
- practical applications
- scientific
What is research support for neutral explanation as a strength??
Ursu and Carter ministered Brian activity in OCD patients using MRI scanners and found hyperactivity in the orbital frontal cortex, exactly what this neural explanations suggests
What are the practical applications for the neural expiations??
As we know OCD suffered have low serotonin we can give them medications to raise serotonin and remove OCD symptoms
This treatment has been particularly successful helping nearly 70% patients that take this medication
Why is neural explanation being scientific a strength??
Neural factors in OCD can be studied in objective and falsifiable ways, for example, a damaged caudate nucleus can be readily identified with scanning devices like FMRI’s
Likewise lower serotonin could be deduced by very sensitive PET scans or by examining cerebrospinal fluids
Helps promote psychology as a scientific subject
What is the most common type of treatment for OCD??
Drug therapy and they work by affecting neurotransmitters in the brain
Why does drug therapy affect neurotransmitters??? For treatment
When neurotransmitters are released into synaptic gap, not all of it attaches to the receptor sites in the receiving neuron. The remaining neurotransmitters must be removed to allow the synapse to return to its normal state.
This is done in one of two ways=
1) re uptake of the remaining neurotransmitter into the presynaptic neuron
2) breakdown of the neurotransmitter in the synaptic cleft by an enzyme
