Ocd Worksheet

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genes | A01 Explanations/Research | Strengths | Weaknesses | | Family and Twin Studies:Evidence for the genetic basis of OCD comes from twin studies and evaluations of first degree relatives. Nastadt et al. (2000) identified 80 patients with OCD and 343 of their first degree relatives and compared them with 73 control patients without mental illness and 300 of their relatives. There was a strong familial link for the most common form of this disorder. People with a first degree relative with OCD (parents or siblings) had a five times greater risk of having the illness themselves at some time in their lives compared with the general population.A meta-analysis of 14 twin studies of OCD, including 80 identical and 29 fraternal twin pairs,…show more content…
When serotonin is released by one cell, it enters the next cell through an area of the cell membrane called the receptor. In OCD, some receptors are thought to block serotonin from entering the cell. This leads to a deficiency in the neurotransmitter in key areas of the brain; i.e. people with OCD may have too little serotonin for their nerve cells to communicate effectively.Dopamine activity:40% of OCD patients do not respond to SSRIs, suggesting that, in some at least, other neurotransmitters are involved. Animal studies have shown that high doses of dopamine aginists induce stereotyped movements in animals that resemble the compulsive behaviours found in OCD patients. Further evidence of dopamine can be found in patients with Tourette’s Syndrome, which are assoiated with the dopamine dysfunction in the basil ganglia. Between 45% and 90% of Tourette’s patients also have obsessions and compulsions. | One strength of the biochemical explanation of OCD is that it has practical applications. For example, Piggott et al. (1990) used drugs that increased the amount of serotonin in the brain such as the selective serotonin reuptake inhibitor (SSRI) Anafranil, which has been shown to reduce the symptoms of OCD. PET scans show lower serotonin levels in OCD patients than control patients. After treatment with SRRIs, the PET scan of an OCD patient looks more like the scan of a normal…show more content…
The abnormality lies mainly in the pathway linking the frontal lobes of the cerebral cortex with the basal ganglia. The frontal lobes are responsible for deliberation and judgement (thinking), while the basal ganglia act as a relay station in the planning and execution of movements (behaviour). PET Scans of patients with active symptoms of OCD show heightened activity in parts of the frontal cortex known as the Orbital frontal cortex (OFC). Obsessive and compulsive symptoms can be caused by a loss of tissue in the caudate nuclei, areas in the basal ganglia that filter messages coming from the OFC before passing the more important ones to other parts of the brain. Researchers suspect that the caudate nuclei form perform this selection function poorly with those with OCD. As suggested by the high level f frontal lobe activity revealed in PET scans, obsessional thinking then persists, often until a compulsive ritual puts an end to it. | One strength of the brain dysfunction theory comes from further empirical support provided by Comer (1998) who suggests that because serotonin plays a key role in the OFC and caudate nuclei, it is likely that low levels of serotonin cause these areas to function poorly. This suggests that there is wider academic credibility for a causal effect between serotonin and regions of the brain. A second strength of the brain dysfunction theory is that it has
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