BIOLOGICAL APPROACH TO EXPLAINING OCD

Question 1

Biological approach

Answer 1

the biological approach assumes mental disorders to be caused due to faulty physical processes.

Question 2

genetic explanation for ocd

Answer 2

the genetic explanation through the diathesis stress model suggests that some people have a genetic vulnerability towards developing ocd.
genetic analysis has revealed around 230 separate candidate genes found in people with ocd. several candidate genes influence the functioning of neural systems in the brain, example the SERT gene affects the seretonin reuptake in seretonin system.

• ocd is polygenic

Question 3

evidence for genetic explanation of ocd

Answer 3

evidence comes from nestadt et al where he previewed previously done twin studies and found that 68% of monozygotic and 31% of dizygotic twins share ocd. this suggests that there is agenetic basis for this disease because monozygotic twins share 100% of their genes and dizygotic twins only share 50% of their genes.

Question 4

evidence against the genetic explanation

Answer 4

cromer et al found that over half of his ocd patients had experienced trauma and there was a positive correlation between increasing trauma and increasing severity of developing ocd.

Question 6

the neural explanation for explaining ocd

Answer 6

neural explanation includes bio chemical causes , an imbalance of neurotransmitters and large neural structures in the brain.

Question 7

seretonin

Answer 7

ocd is thought to be caused by low seretonin levels in the brain.
- low seretonin level is likely to be caused because its taken away from the synapse too quickly before it has been able to pass the signal.

Question 8

SERT gene

Answer 8

gene responsible for the transport of seretonin in the synapse.

Question 9

brain structures and ocd

Answer 9

basal ganglia and orbito frontal complex

Question 10

basal ganglia

Answer 10

basal ganglia is a brain structure involved in different processes. patients who suffer head injuries in this region often develop ocd like symptoms. Max et al (1994) found that when the basal ganglia is disconnected from the frontal cortex during surgery, ocd like symptoms are reduced providing further support for role of basal ganglia in ocd.

Question 11

orbito frontal complex

Answer 11

• converts sensory information into thoughts and actions,
• pet scans have found higher activity in ofc in patients with ocd.
• one suggestion is that increased activity in the orbito frontal complex causes increase in conversion of sensory information to behaviours and thus which results in compulsions.
• include caudate nucleus

Question 12

strength ao3 for biological explanation of ocd

Answer 12

• neuroimaging studies using PET scans have shown hyperactivity in the orbitofrontal complex and caudate nucleus in people with ocd, when scanning the brain at rest and when the brain is stimulated
• however there is a probem with neural studies as it is correlational and researchers are not sure if hyperactivity is a cause or consequence of ocd.

Question 13

ao3 neutral point

Answer 13

a meta analysis by soomro et al demonstrated that SSRis are more effective than placebos suggesting there is a biological approach to ocd, however these drugs takes weeks to reduce the symptoms and 40% to 60% of patients show no improvement so findings suggests that low levels of seretonin play a role in ocd but is not the sole cause of ocd.

Question 14

diathesis stress model

Answer 14

diathesis stress model maybe a valid explanation for ocd than biological explanation, as it explains that individuals inherit a genetic vulnerability to ocd, however the disorder doesnot develop until there is an environmental factor such as a traumatic experience.
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Question 15

biological approach to treating ocd

Answer 15

drug therapy

Question 16

SSRIs

Answer 16

Selective Seretonin Reuptake Inhibitors inhibit the reuptake process in synapse so that seretonin is still present in the synaptic cleft to stimulate the post synaptic neuron which decreases anxiety.

Question 17

benzodiazepines ( anti anxiety drug)

Answer 17

these work by enhancing neurotransmitter like GABA slowing down the central nervous system and resulting in general relaxation.

Question 18

tricyclics and SNRis

Answer 18

works by increasing seretonin and noradrenaline but tends to have intense side effects as they work on multiple neurotransmitters

Question 19

ao3 for drug therapies ( evidence for strength)

Answer 19

• soomro et al conducted a meta analysis from 17 studies where he found that SSRIs were effective comapred to placebos and it helped in reducing the symptoms of ocd compared to placebos in between 6 and 17 weeks post treatment.

Question 20

strength for drug therapy

Answer 20

• inexpensive and convenient as compared to cbt as patients dont have to find time for multiple sessions as well as a trained therapist.

Question 21

limitation for drug therapy ao3

Answer 21

• goldacre points out that most research on drug therapied are conducted by the pharmeutical companies selling them with a motive of financial interest. also results in a file drawer problem that the negative results may stay unpublished.
• many patients prefer cbt eventhough drug therapy is convenient and inexpenisve, it has intense side effects. in soomor et als meta analysis nausea, insomnia and headache were the most common symptoms.