Psychopathology - OCD

Question 1

How does the biological approach explain OCD?

Answer 1

• explains mental health conditions as to being due to faulty physical processes
• symptoms of OCD include obsessive thoughts and compulsive behaviours
• obsessive thoughts are distressing mental images or concerns that provoke anxiety
• compulsions are actions that individuals feel they need to perform - to reduce the discomfort caused by these thoughts

Question 2

What does the genetic explanation suggest about OCD?

Answer 2

• thought a vulnerability or predisposition to OCD is inhibited from parents
• 230 separate ‘candidate genes’ are found more frequently in people with OCD
• evidence from heritability of OCD comes from family and twin studies

Question 3

In terms of the genetic explanation, what does it suggest about candidate genes and its influence on OCD?

Answer 3

• many candidate genes influence the functioning of neural systems in the brain
  e.g . SERT gene affects reuptake in the serotonin system
• other identified genes:
  Gene 9, COMT gene and 5HTI-D beta gene

Question 4

In terms of the genetic explanation of OCD, what does it mean when many candidate genes are identified?

Answer 4

• many candidate genes identified suggests OCD is polygenic
• meaning predisposition to OCD requires a range of genetic changes

Question 5

How does the neural explanation (in terms of biochemical causes) explain OCD?

Answer 5

• neural explanations include biochemical causes,, an imbalance of neurotransmitters and the large neural structures in the brain that are made of neurons
• low serotonin levels are thought to cause obsessive thoughts
• low serotonin is likely due to being removed too quickly from the synapse
• before it has been able to transmit its signal / influence the postsynaptic cell
• SERT gene is the gene responsible for serotonin transportation in the synapse

Question 6

How does the neural explanation (in terms of the ‘worry circuit’ ) explain OCD?

Answer 6

• the “worry circuit” - communication between the orbitofrontal complex (OFC) (rational decision making), the basal ganglia system, the caudate nucleus and the thalamus
• in the worry circuit appears to be overactive in people with OCD
• brain structures if hyperactive could form a loop (recurring obsessive thoughts)
• Parahippocampal gyrus - an area of cortex which regulates and processes unpleasant emotions and has been seen to function abnormally in cases of OCD

Question 7

Strengths of the biological approach in explaining OCD

Answer 7

• Nestadt (2010) shows for OCD - there is a high concordance rate between close family members
• non- identical twins - 30% concordance
• identical twins - 81% concordance
• MZ and DZ twins grow up sharing similar environments like food, upbringing, education, life events etc.
• suggests additional shared DNA is responsible for increased concordance

Question 8

Weaknesses of the biological approach in explaining OCD

Answer 8

• correlation in family and twins does not automatically equal causation
• it may not be the shared genetics behind high concordance rates
• identical monozygotic twins may be treated more similarly because they look alike, compared to dizygotic, non-identical twins
• concordance rates for identical twins is at 68% not 100%
• the level we expect for an entirely genetic determined psychological feature
• so there must be some role of environment

Question 9

In terms of weaknesses of the biological approach explaining OCD, what did Cromer’s research show?

Answer 9

• Comer showed 54% of 265 participants with OCD reported at least one traumatic life events
• and those with traumatic life events reported increased severity of OCD symptoms
• this demonstrates an environmental aspect of OCD

Question 10

Describe drug therapy in treating OCD

Answer 10

• primary class of drugs used to control symptoms of OCD
• are a group of antidepressant drugs called SSRIs
• SSRIs are called selective serotonin reuptake inhibitors
• that inhibits the reuptake process in the synapse
• this decreases anxiety by normalising the activity of the worry circuit

Question 11

In terms of drug therapy treatment, describe how some patients can overcome ineffective SSRIs

Answer 11

• SSRI’s can take 3-4 months to reduce symptoms
• for some patients, SSRIs are not effective
• dosage can be increased for drug - resistant patients or other treatment options attempted
• such as anti-anxiety drugs like benzodiazepines

Question 12

Strengths of drug therapy in treating OCD

Answer 12

• Soomro conducted a meta analysis combining the data from 17 studies that compared SSRIs to placebos
• this showed that SSRIs significantly reduced symptoms of OCD compared to placebos between 6-17 weeks post-treatment