characteristics + explanations of OCD Flashcards
what are the behavioural characteristics of OCD?
- compulsions (repetitive + intrusive thoughts focused around the stimulus which reduce anxiety)
- avoidance behaviour (negative reinforcement)
what are the emotional characteristics of OCD?
- guilt
- disgust
- depression (due to constant compulsions)
- anxiety (acknowledgement that obsessive thoughts are irrational)
what are the cognitive characteristics of OCD?
- obsessive thoughts
- insight into excessive anxiety
- hyper-vigilance (constant alertness)
what are the 2 explanations for OCD?
- genetic
- neural
what does the genetic explanation for OCD suggest?
- suggest that individuals inherit specific genes that cause OCD.
- OCD seems to be polygenic (several genes are involved)
what are the 2 genes linked to OCD?
- the SERT gene
- the COMT gene
what is the SERT gene’s role in OCD?
the SERT gene is mutated in individuals with OCD, this causes increased re-uptake of serotonin in the neuron, decreasing levels of serotonin in the synapse
- less serotonin = increased OCD
what is the COMT gene’s role in OCD?
COMT is responsible for clearing dopamine from synapses and low activity of the COMT gene is also associated with OCD
- high dopamine = increased OCD
what does the neural explanation for OCD suggest?
neural explanations suggest that brain structures and regions are implicated in OCD
what is the the role of the pre-frontal cortex in OCD?
- the pre-frontal cortex is involved in decision making, an over-active PFC causes an exaggerated control of primal impulses
give an example of an over-active PFC in OCD
if you go to the bathroom, your primal instinct is to wash your hands, the PFC then reduces in activation after
- in OCD patients, the PFC is over-activated, meaning that obsessions and compulsions continue, leading to repetitive hand washing etc.
S genetic: supporting evidence (Nestadt) + ELAB: concordance rates
ID: there is supporting evidence for the genetic explanation of OCD
Q: Nestadt conducted twin studies and found support for the genetic link to OCD
EX: Nestadt conducted research by reviewing previous twin studies of OCD. he found that 68% of identical twins, compared to 31% of non-identical twins, shared OCD
AN: this strongly suggests that there is a genetic basis for this disease because identical twins share 100% of their genes with each other, whilst dizygotic twins only share 50% of genes with each other
ELAB: however, no twin study has found a concordance rate of 100% in identical twins, which means that biological factors are not the only factor contributing to OCD and there must be environmental factors which also contribute to this disorder.
W: may be reductionist
ID: however, a criticism of biological explanations of OCD is that they may be reductionist
Q: it ignores other factors, as it doesn’t take into account cognitions and learning
EX: for example, some psychologists suggest that OCD may be learnt through CC and maintained through OC. for example, a cognitive explanation of OCD may see the sufferer as having persistent irrational thoughts that focus on anxiety-generating stimuli (e.g. a thought that germs are everywhere and going to infect and kill them). behaviours that reduce the anxiety associated with these thoughts (e.g. cleaning) become compulsions through operant conditioning.
AN: therefore, the biological explanation may be criticised for being biologically deterministic in explaining behaviour
W: too many candidate genes
ID: a weakness of the biological explanation is that there are too many candidate genes involved
Q: this means that it is difficult to isolate OCD onto a specific gene
EX: for example, with over 230 candidate genes, each individually coding for an increased risk of OCD, this poses a practical issue as it is difficult to assess which genes have the greatest influence on OCD, and which genes drug treatments should target
AN: therefore, such an explanation is likely to have little predictive value in the future, decreasing practical applications, such as drug treatments
