| What are obsessions? | Thoughts, a persistent thought, idea, impluse, or image that experienced repeatedly, feels intrusive and causes anxiety |
| What are compulsions? | Behaviour, a repetitve and rigid behaviour or mental act that a person feels driven to perform in order to prevent and reduce anxiety |
| What is the genetic explanation of OCD? | Genetic explanation: suggests that OCD is inherited and that individual receive specific genes from their parents which influence the onsent of OCD |
| What is the neural explanation of OCD? | Suggest that abnormal levels of neurotransmitters (serotion and dopmaine) and certain regions of the brain are implicated in OCD |
| Nestadt conclusion for OCD study? | Found that first-degree relatives of OCD sufferers had a higher chance of developing the disorder |
| What specific findings did Nestadt obtain in his study? | 12% chance for those with first degree relatives diagnosed OCD
3% risk for control group |
| What is the genetic explanation focused on? | -Identifying specific candidate gene which are implicated in OCD
-OCD is a polygenic condition - several genes involved |
| What did Taylor suggest about OCD? | Taylor suggests that as many as 230 genes may be involved in the condition and perhaps differernt genetics contribute to the different types of OCD, hoarding or obsessions with religion
Aetiologically heterogenous, origins vary from one person to another |
| What are two examples of genes of OCD? | COMT and SERT genes |
| What is COMT gene associated with? | Associated with the production of catechol-O-methytransferase (COMT) which regulates the neurotransmitter dopamine |
| How does COMT gene relate to OCD? | A variation of COMT gene results in higher levels of dopamine and is more common with patients with OCD than without |
| What is the SERT gene also known for? | SERT gene is also known as the 5-HTT gene which is linked to sertonin and affects the transport of the neutotransmitter |
| What do transportation issues do with serotonin? | Transportation issues cause lower level of serotonin to be active within the brain and are associated with OCD (and depression) |
| What did Ozaki find with the SERT gene? | Ozaki published results of 2 unrelated families who both mutations of the SERT gene. It coincided with 6/7 of the family members having OCD |
| What is the neural explanation when related to OCD? | The genes produced chnages in neurotransmitters in the brain
Neurotransmitters are important for communication within the brain
They can either excite or inhibit neurons - either increase or decrease brain activity |
| What serotonin do? | Serotonin regualr mood and lower levels of serotonin are associated with mood disorders, such as depression |
| How does SERT cause OCD, relate to a study? | Some cases of OCD are related with low levels of serotonin, casued by the SERT gene
Pigott study exaimed antidepressants, found that drugs that increase the level of serotonin in the synaptic gap are effective in treating patients with OCD |
| What is higher level of dopamine assocaited with? | Some symptoms of OCD, like complusive behaviours |
| What regions of the frontal lobe have been abnormal brain circuits with ppts with OCd? | -Basal ganglia
-Orbitofrontal cortex |
| What is the basal ganglia ? | A cluster of neurons at the base of the forebrain, multiple process including the coordination of movement
Patients who suffer head injuries in this region often develop OCD-like symptoms |
| What is the orbitofrontal cortex? | Region that converts sensory information thoughts and actions. |
| What has PET scans find in the orbitofrontal cortex? | Found that higher activity in the orbitofrontal cortex in patients with OCD when a ppt was asked to hold a dirty item with a germ hazard.
Heightened activity suggests that there is an increase of the conversion of sensory information to actions which results in complusions |
| What is the parahippocampal gyrus? | Evidence to suggest that its function of processing unplesant emotions, functions abnormally in the brain of people with OCD |
| What is a strength of the genetic explanation? | -Research support to suggest that there is a link between genetics and OCD from twin stuides
-Nestadet found higher concordance rates in MZ twins compared to DZ tiwns. 68% concordance rate for MZ twins and 31% concordance rate for DZ twins
-Billet conducted a meta-analysis of 14 twin stuides, found that MZ twins are x2 more likely to develop OCD if their co-twin had OCD.
-Though it shows a link betwen OCD and genetic makeup, it can't be said that its only genetic seeing as there isn't a 100% concordance rate - suggests that there are other factors that play a part in OCD, like the daithesis-stress model |
| What is weakness of the genetic explanation ? | -There are environmental risk factors
-There is strong eveidence for the idea that the genetic variation can make a person more or less vunerable to OCD. However, OCD does not appear to be entirely genetic in origin and it seems that environmental risk facts can also trigger or increase the risk of developing OCD
-An example, study Kiara Cromer found that over hald the OCD clients in the sample had experienced a traumatic even in their past. OCD was also more severe in those with one or more traumas
-This means that genetic vulnerability only provides a partial explanation for OCD and environmental factors should be taken into account |
| What is a strength of the neural explanation? | -Reserach support to sugges that there is a link between the neural model and OCD which comes from twin studies
-Menzies use MRI to produce imgaes of brain activity in OCD patients. Their brain images are compared to those of their immediate family memebers who did not have OCD (parent, sbilings, child) and a control group unrelated healthy people.
-Found that OCD ppts and thier immediate family had reduced grey matter in key regions of the brain including the OFC.
-Means that if an aduly has OCD, it can be assumed that their OCD may be passed down to their child meaning that the child could then themselves be detected for future risks of developing OCD |
| What is a weakness of the neural explanation? | -The serotonin-OCD link may not be unique to OCD
-Many people with OCd also experience clinical depression. Having 2 disorders together is called co-morbidity.
-This depression probaly invovles (though is not necessarily caused by) disruption to the action of serotonin. This leaves use with a logical problem when it comes to serotonin as possible basis for OCD
-It could simply be that serotonin activity is disrupted in many people with OCD because they are depressed as well. This means that serotonin may not be relevant to OCD symptoms |
