Psychopathology: OCD Flashcards
Behavioural Characteristics Of OCD.
- Compulsive behaviour is the behavioural component of OCD. Compulsions are repetitive usually sufferers feel compelled to repeat a behaviour.
- Compulsions Reduce Anxiety - 10% of OCD sufferers don’t have obsession just compulsive. For a lot of individuals compulsions are performed to manage their anxiety that is produced by the obsession.
- Avoidance - OCD sufferers attempt to reduce anxiety by keeping away from situations what triggers it.
Emotional Characteristics Of OCD.
- Anxiety And Distress - obsessive thoughts are unpleasant, frightening and the anxiety can be overwhelming. The urge to repeat a behaviour (a compulsion) also creates anxiety.
- Depression - OCD is often accompanied by depression as sufferers have low mood.
- Irrational guilt over minor moral issues.
- Disgust often directed to something external or at the self.
Cognitive Characteristics Of OCD.
- Obsessive Thoughts - 90% OCD sufferers have this as their major cognitive feature where thoughts reoccurs over and over again. They vary from person to person but always unpleasant.
- Cognitive Strategies - adopted to deal with obsession and manage anxiety associated with them. For example a religious person tormented by obsessive guilt may respond by praying.
- Insight Into Excessive Anxiety - OCD sufferers aware that their obsessive and compulsions are not rational. It is a symptom that is needed for diagnosis.
Genetic Explanation For OCD.
- Focuses on the role that genes play in the development of a mental disorder. There are 4 different genetic explanations.
1) Genes are involved in an individual’s vulnerability to OCD. Lewis observed that his OCD patients 37% had parents with OCD and 21% had siblings with OCD. Suggests that OCD runs as a family rather than a gene which definitely produce OCD. The diathesis stress model suggest that certain genes leave some environmental stress, (experience) that triggers the OCD.
2) Research has found candidate genes that create vulnerability for OCD. Some of these genes are involved in regulating the development of the serotonin system - a neurotransmitter which is involved in OCD. One of the genes thought to be involved in OCD vulnerability is the gene 5HTI -D beta which is involved in the efficiency of transport of serotonin across synapse.
3) OCD is polygenic meaning that is not caused by one single gene but that several genes are involved. Taylor analysed finding of previous studies and found evidence that up to 230 difference genes may be involved in OCD. These genes are thought to be associated with the action of dopamine as well as serotonin - both regulating mood.
4) OCD is aetiology heterogeneous meaning that the origin of OCD has different causes. One group of genes may cause OCD in one person, but a different group of genes may cause the disorder in another person. There is some evidence to suggest that difference types of OCD, such as hoarding and religious obsessions may be due to particular genetic variations.
Genetic Explanation Evaluation: Strength - Twin Studies Support.
- There is evidence from a variety of sources for the idea that some people are vulnerable to OCD as a result of genetic make-up.
-Nestadt et al reviewed previous twin studies and found that 68% of identical twins shared OCD as opposed to 31% of non-identical twins. - This strongly suggests that there is a genetic influence on OCD.
Genetic Explanation Evaluation: Weakness - Flawed Evidence.
- Twin studies are flawed as genetic evidence.
- There are standard source of evidence for genetic influences, but they assume that identical twin studies are only more similar than non-identical twins in terms of their genes.
- They look over the fact that identical twins may also similar in terms of shared environments.
- For example, non-identical twins might be a boy and a girl who have different experiences.
- This reduces the value of twin studies as the evidence does not separate that effects of nature and nurture on OCD, thus reducing the supporting evidence for the genetic explanation of OCD.
Genetic Explanation Evaluation: Weakness - Cannot Not Identify All OCD.
- Despite twin studies suggesting that OCD is largely genetic, psychologists have not been successful in identifying all of the genes involved.
- One reason for this is because there are several genes involved in OCD and each genetic variation only increase the risk of OCD by a fraction.
- The consequence is that a genetic explanation is unlikely to be very useful is provides little predictive values about whether an individual will develop OCD and if so, what type.
Genetic Explanation Evaluation: Weakness - Environmental Factors.
- There is evidence that environment factors can also trigger, or increase the risk of developing OCD.
- Cromer et al found that over half the OCD patient in their sample had a traumatic event in their past, and that OCD was more severe in those who had more than one trauma.
- This suggests that OCD cannot be entirely genetic in origin.
- It may therefore by more productive to focus on environmental causes because we are more able to do something about these.
Neural Explanation For OCD.
- Explanation focuses on the structure and function of the brain and nervous system in the development of a mental disorder.
1) Some cases of OCD are explained by a reduction in the functioning of the serotonin system in the brain meaning that less is produced. Serotonin is a neurotransmitter responsible for regulating mood. Low serotonin means that a normal transmission of mood-relevant information between neurons does not take place and mood and other processes are affected. A mutation on the SERT gene may contribute to this.
2) Dopamine levels are thought to be highly abnormal in people with OCD. High doses of drugs that enhance levels of dopamine were given to animals induce stereotyped movements resembling the compulsive behaviour founded in OCD patients.
3) Decision making occurs in the lateral frontal lobes. Abnormal functioning in LFL leads to impaired decision making. Impaired decision making is thought to be responsible for hoarding disorder.
4) The left parahippocampal gyrus may also be involved in OCD. This area of the brain is associated with processing unpleasant emotions. It has been found to function abnormally in those with OCD.
Neural Explanation Evaluation: Strength - Anti-depressants And High Serotonin.
- Evidence for the role of serotonin in OCD comes from research examining anti-depressants.
- This research has found that drugs which increase the level of serotonin are effective in treating patients with OCD.
-This suggests that serotonin is involved in OCD.
Neural Explanation Evaluation: Strength - Co-Morbidity And Anti-Depressants.
- The serotonin OCD link may simply be co-morbidity (having two disorders together) with depression.
- Many people who suffer OCD become depressed.
- This depression probably involves disruption to the serotonin system.
- It could be that in those individuals with OCD that the serotonin system is disrupted because they are depressed as well.
- However, the fact that types of antidepressants that do not work on the serotonin system have no affect on OCD suggests that serotonin is directly involved in OCD and not just accompanying depression.
Neural Explanation Evaluation: Weakness - Neural Mechanisms Are Unknown.
- It is not clear exact which neural mechanisms are involved in OCD.
- Cavedini et al looked at decision making and found that the neural systems that are involved in decision making are the same systems that are functioning abnormally in those with OCD.
- This suggests that these areas of the brain are implicated in OCD.
- However, research has also identified other brain systems that are sometimes involved in OCD.
- The problem is that no brain system has been found to always play a role in OCD.
- Therefore we do not which neural mechanisms are involved in the development of OCD.
Neural Explanation Evaluation: Weakness - No Causality.
- It should not be assumed that neural mechanisms cause OCD.
- There is evidence to suggest that various neurotransmitters and brain areas do not function normally in patients with OCD.
- However, this is not the same as saying that this abnormal functioning cause OCD.
- These biological abnormalities could be result of OCD rather than its cause.
What Are The Aims Of Drug Therapy?
- Drug therapy is treatment that aims to increase or decrease levels of neurotransmitters in the brain in order to increase or decrease the neurotransmitter activity.
Biological Treatment For OCD: SSRIS Process.
- OCD thought to be caused by low levels of serotonin, drug treatment for OCD involves increasing the level of serotonin in the brain.
- Involves a type of anti depressant known as a selective serotonin reuptake inhibitors (SSRI).
- Works in the brain by preventing the re-absorption and break down of serotonin by the pre-synaptic neuron.
- Levels of serotonin in the synapse increase and can continue to stimulate the postsynaptic neuron.
