Biological Approach to Explaining OCD Flashcards
(21 cards)
AO1 for biological approach to explaining OCD
- OCD – obsessive compulsive disorder, a condition characterised by obsessions and/or compulsive behaviour. Obsessions are cognitive whereas compulsions are behavioural
- Behavioural – ways in which people act
- Emotional – related to a persons feeling or mood
- Cognitive – refers to the process of ‘knowing’ including thinking, reasoning, remembering, believing
- Biological approach – a perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function
- Genetic explanations – genes make up chromosomes and consist of DNA which codes the physical features of an organism (such as eye colour, height) and psychological features (such as mental disorder, intelligence). Genes are transmitted from parents to offspring, i.e. inherited
- Neural explanations – the view that physical and psychological characteristics are determined by the behaviour of the nervous system, in particular the brain as well as individual neurons
AO3 (1) biological approach to explaining OCD
- A strength of the genetic explanation for OCD is the strong evidence base.
- For example, in a study, Nestadt et al reviewed twin studies and found that 68% of identical twins (monozygotic) shared OCD as opposed to 31% of non-identical (dizygotic) twins. Additionally, research has found that a person with a family member diagnosed with OCD is around four times as likely to develop it as someone without
- This is a strength as it suggests that some people are vulnerable to OCD as a result of their genetic make-up, showing that biological genes play a role when it comes to a person forming OCD
- However, it can be argued that OCD does not appear to be entirely genetic in origin and it can be triggered by environmental factors showing that the genetic model for OCD is limited as genetic vulnerability is only a partial explanation for OCD
- Despite this, research studies suggest that there must be some genetic influence on the development of OCD
- Thus increasing the validity of genetic explanations for OCD
AO3 (2) biological approach to explaining OCD
- A strength of the neural explanation of OCD is the existence of some supporting evidence
- For example, Antidepressants that work purely on serotonin are effective in reducing OCD symptoms
- This is a strength because it suggests that serotonin may be involved in OCD, thus making it easier to treat/reduce
- However, it can be argued that serotonin may not be relevant to OCD symptoms as many people with OCD tend to also experience clinical depression meaning it could be the depression causing disruption to serotonin activity for many people with OCD
- Despite this, the supporting evidence suggests that biological factors like serotonin and the processes underlying certain disorders may also be responsible for OCD
- Thus increasing the validity of neural explanations for OCD
AO3 (3) biological approach to explaining OCD
- A weakness of the biological approach for explaining OCD is that it is reductionist
- For example, the behaviourist approach argues that OCD in relatives is actually a learned behaviour and not genetics, as a child may observe and imitate behaviours displayed by a parent with OCD but the biological approach does not take this into account
- This is a weakness as it shows that the biological approach is limited as it ignores other influences on OCD like social influences and cultural influences, therefore reducing its usefulness for explanations of OCD
- However, it can be argued that the biological approach is reliable as it uses objective and observable techniques such as neuroimaging to study OCD and has led to the development of successful treatments for OCD such as SSRI, showing its findings have scientific validity
- Despite this, the biological approach focuses on only genetic and biological influences showing its reductionism
- Thus reducing the validity of the biological approach for explaining OCD
explain the AO3s for the biological approach to explaining OCD
strength - strong evidence base. Nestadt et al reviewed twin studies and found that 68% monozygotic twins shared OCD as opposed to 31% dizygotic showing that some ppl are vulnerable to OCD based on their genetic make-up, however it can be argued OCD does not appear to be entirely genetic in its origin, despite this research studies suggest there must be some genetic influence on development of OCD
strength - supporting evidence - antidepressant work purely on serotonin and are effective in reducing OCD symptoms, strength cuz suggests serotonin is linked with OCD making it easier to treat/reduce, however serotonin may be not be relevant to OCD ad many ppl with OCD tend to also experience clinical depression so the depression could be causing the disruption to the serotonin activity, despite this supporting evidence suggests bio factors like serotonin & certain underlying disorders may also be responsible for OCD
weakness - reductionist - behaviourist believe OCD is a learned behaviour and not in genetics, bio limited doesn’t take into account cultural influences, however reliable as uses objective and observable techniques like neuroimaging to study OCD & led to development of successful treatments for OCD like SSRIs, so scientific validity, despite this only focuses on genetic and biological influences = reductionism
family studies
Family studies have shown that relatives of OCD are more vulnerable to developing OCD. For example, Nestadt et al (2000) found that first-degree relatives (i.e. parents, siblings) of OCD sufferers had an 11.7% chance of developing the disorder compared to a 2.7% risk in first-degree relatives of control patients without OCD.
twin studies
Twin studies have also been used to investigate the role genetics play in
developing OCD. They involve a comparison between identical twins (monozygotic – MZ) and non-identical twins (dizygotic – DZ). MZ twins share 100% of their genes and DZ share only 50% of their genes so if genes do play a role in developing OCD we would expect to find a higher concordance rate for MZ than DZ. For example, Carey and Gottesman (1981) found MZ twins has a concordance rate of 87% for obsessive symptoms and features compared to 47% in DZ twins.
what is concordance rates
The probability that a pair of individuals will both have a certain characteristic, given
that one of the pair has the characteristic.
COMT gene
The COMT gene regulates the neurotransmitter dopamine. One variation of the COMT gene results in higher levels of dopamine and this variation has been found to be more common in patients with OCD, in
comparison to people without OCD.
SERT gene
The SERT gene (also known as the 5-HTT gene) is linked to the neurotransmitter serotonin and affects the transport of the serotonin (hence Serotonin Transporter), causing lower levels of serotonin which is also associated with OCD (and depression)
what does it mean if OCD seems to be polygenic
However, OCD seems to be polygenic. This means that OCD is not caused by one single gene but that several genes are involved. Taylor (2003) suggests that as many as 230 genes may be involved and different genetic variations contribute to the different types of OCD.
strengths of the biological approach to explaining OCD ~ genetic explanations
supporting evidence from twin and family studies - Nestadt et al
limitations of the biological approach to explaining OCD ~ genetic explanations
issue with the research investigating the role of genetics
diathesis-stress model - suggests that an interactionist approach more appropriate
what are biochemical causes
Biochemical causes (neurotransmitters): Neurotransmitters, in particular serotonin and dopamine, have been found to play a role in OCD.
what is serotonin and an example
Serotonin: If a person has low levels of serotonin then normal transmission of mood-relevant information does not take place which means mood, and sometimes other mental processes, are affected. For example, when low serotonin levels are experienced by someone with OCD, it can make them edgier and more hyperaware of their environments than usual, resulting in increased OCD-related behaviours such as obsessive hand-washing, counting or organizing.
what did Piggot et al (1990) find
Piggott et al (1990) found that drugs which increase the level of serotonin in the synaptic gap are effective in treating patients with OCD, suggesting that serotonin is a contributory factor.
what is dopamine and link it to OCD
Dopamine: High levels of dopamine have been linked to OCD. This may be because dopamine is thought to influence concentration which could explain why OCD individuals experience an inability to stop focussing on obsessive thoughts and repetitive behaviours.
info on neurophysical causes
Neurophysiological causes (areas of the brain):
Research has found sufferers of OCD have elevated levels of activity in the
orbitofrontal cortex and the caudate nucleus
(located in the basal ganglia).
PET scans of patients with OCD have shown
higher levels of activity in the OFC. The
orbitofrontal cortex is part of a brain circuit; one of the functions of this
circuit appears to be turning sensory information into thoughts and
actions. Primitive impulses, for example to check and clean, arise from
the orbitofrontal cortex in response to sensory inputs.
limitations of the biological approach to explaining OCD ~ neural explanations
strengths of the biological approach to explaining OCD ~ neural explanations
brain-imaging research shows elevated activity in the orbital region and the caudate nucleus consistently in OCD patients supporting the neurophysical explanation as it shows that these areas of the brain are linked to OCD
limitations of the biological approach to explaining OCD
biological reductionism
