PAPER 1 - PSYCHOPATHOLOGY - biological approach to explaining & treating OCD

Question 1

what is the fundamental belief of the biological apporach?

Answer 1

behaviour is a result of genetics and naurotransmitters

Question 2

what is the role o the COMT gene in the development of OCD?

Answer 2

COMT regulates production of dopamine which has been implicated in OCD & this variation leads to lower activity of the COMT gene and high levels of dopamine
- more commonly found in those with OCD

Question 3

what is the role of the SERT gene?

Answer 3

• involved in transport of seratonin-mutation of this gene
• leads to lower levels of serotonin
• Ozaki (2003) found mutation of this gene in 2 unrelated families, 6 of 7 members had OCD

Question 4

how is the role of genetics investigated?

Answer 4

family studies - especially MZ twins

Question 5

what does diathesis stress suggest?

Answer 5

• genes create genetic vulnerability to mental disorders (diathesis) but other factors (stressors) influence development of a disorder
• simple link between one gene and a complex disorder like OCD is unlikely

Question 6

how is dopamine associated with OCD?

Answer 6

• dopamine affects motivation and ‘drive’
• dopamine levels are thought to be abnormally high in people with OCD
• high levels of drugs that enhance levels of dopamine induce stereotyped movements - showing behaviours found in OCD

Question 7

how is serotonin associated with OCD?

Answer 7

• lower levels of serotonin are associated with OCD, based on antidepressant drugs that increase serotonin activity decrease OCD symptoms
• antidepressants with less of an effect on serotonin don’t reduce OCD symptoms

Question 8

what is the worry circuit (abnormal brain circuit) in the brain?

Answer 8

• several areas in frontal lobes of the brain are thought to be abnormal in people with OCD
• caudate nucleus normally suppresses signals from orbitofrontal cortex (OFC)
  OFC sends signals to thalamus about things that are worrying
• if caudate nucleus is damaged it cant suppress minor ‘worry’ signals so acts as a worry circuit

Question 9

evaluation for explaining OCD - what is the research from family studies?

Answer 9

• Nestadt (2003) found people with first degree relative with OCD had 5x greater risk of developing it
• twin studies show MZ twin twice as likely to develop OCD if twin had it compared to DZ twins
• HOWEVER concordance rates are never 100% which means environmental factors must play a role too (diathesis-stress)

Question 10

evaluation for explaining OCD - what is the research support for genes and OFC?

Answer 10

• many studies demonstrate genetic link to abnormal levels of neurotransmitters
• researchers used MRI to produce images of brain activity in OCD patients and immediate family members
• OCD patients & close relatives had reduced grey matter in key regions of the brain including OFC
• supports anatomical differences are inherited and may lead to OCD

Question 11

evaluation for explaining OCD - what is the real world application for explaining OCD?

Answer 11

• mapping of human genome led to hope that specific genes could be linked to particular mental and physical disorders
• it gives opportunities for early intervention like termination of eggs however that raises ethical issues
• presumes there is a simple relationships between a disorder and genes (unlikely) so mapping of genome is controversial

Question 12

what are SSRIs? (drug therapy)

Answer 12

• type of antidepressant (Selective Serotonin Reuptake Inhibitors)
• lower levels of serotonin associated with OCD
• inhibit reabsorption of serotonin after its been received by receptor cells
• less addictive

Question 13

what are tricyclics? (drug therapy)

Answer 13

• type of antidepressant
• primarily used for OCD
• blocks transporter mechanism that absorbs serotonin & noradrenaline
• both neurotransmitters are left in synapse to prolong activity
• treat more than one neurotransmittter

Question 14

what are benzodiazapines? (drug therapy)

Answer 14

• type of anti-anxiety drug
• slows activity of CNS by enhancing action of GABA (calming neurotransmitter)
• GABA receptors increase flow of chloride ions that make it harder for neuron to be stimulated by other neurotransmitters
• individuals then feel more relaxed

Question 15

evaluation for treating OCD - what is the evidence for effectiveness of drug therapy?

Answer 15

• lots of evidence for effectiveness
• randomised control trial is used to compare effectiveness of drugs vs placebo (random allocation to drugs)
• researchers reviewed 17 studies of use of SSRIs with OCD patients, found them to be more effective than placebos - reduced symptoms of OCD up to 3 months after treatment
• studies only show short term benefits

Question 16

evaluation for treating OCD - what are the advantages of drug therapy to a) the individual? b) the health service?

Answer 16

a) requires little input (less time & effort) - contrasting to CBT
b) requires little monitoring & cheaper than psychological treatments

Question 17

evaluation for treating OCD - what are the possible side effects of drug treatment?

Answer 17

• nausea, headache, insomnia - common side effects of SSRIs and can make patient stop taking the drug
• tricyclic antidepressants can cause hallucinations, irregular heart beat
• benzodiazapines can cause aggression & long term impaired memory

Question 18

evaluation for treating OCD - what is the possible advantage to drug treatment compared to CBT?

Answer 18

• not long lasting cure for OCD
• researchers found patients relapse within a few weeks if medication stopped

Question 19

evaluation for treating OCD - what is meant by publication bias?

Answer 19

• publishing overly positive results
• Turner et al found evidence for publication bias towards studies that show positive outcome of antidepressant treatment
• leads to doctors making inappropriate treatment decisions