Psychopathology: Biological approach to OCD

Question 1

What does the biological approach say about OCD

Answer 1

• assumes psychological disorders are physical illnesses with physical causes.

Question 2

(+) Explain the Evidence FOR genetic factors to OCD (Billet) (Pauls)

Answer 2

• Billet et al -> meta-analysis of twin studies.
  -> for identical twins, if one had OCD then 68% of the time both had it.
  -> compared to 31% for non identical twins.
• Pauls et al -> 10% of people with an immediate relative with OCD also suffered.
  -> compared to around 2% of people in the general population.

Question 3

(-) explain the evidence AGAINST the biological approach to OCD

Answer 3

• No study has proved 100% concordance route -> genetics can’t be the full story.
  -> possible that children IMITATE behaviour of relatives instead.
• Concordance rates don’t prove OCD is caused by genetics.
  -> may be that general anxiety is genetic and going on to develop OCD has other contributing factors -> e.g. biochemical or psychological factors.

Question 4

(+) explain the biochemical factors in OCD (FOR) (Insel) (Zohar)

Answer 4

• PET scans show levels of serotonin are lower in OCD sufferers.
• Insel -> found that the class of drugs, SSRIs, which increase levels of serotonin can reduce symptoms of OCD in 50-60% of cases.
• Zohar et al -> found SSRIs alleviated symptoms in 60% of patients with OCD.

Question 5

(-) explain evidence AGAINST biochemical factors in OCD

Answer 5

• SSRIs don’t offer relief in 100% of cases -> may be more to understanding OCD.
• Link with serotonin is correlational -> doesn’t show the cause and effect of OCD.
  -> Decreased serotonin levels may be a symptom rather than a cause.

Question 6

(+) explain the neurological factors of OCD (Evidence for) (Max)

Answer 6

• Max et al -> increased rated of OCD in people after head injuries that cause brain damage to the basal ganglia.
• research found increased activity in this area during OCD related behaviours.
• OCD is often found with other diseases that involve the basal ganglia.
  -> E.g. Parkinson’s and Huntington’s disease.

Question 7

(-) explain evidence against neurological factors of OCD (Evidence for) (Aylward)

Answer 7

• found no significant difference in basal ganglia impairment between OCD patients and controls.
• basal ganglia damage hasn’t been found in 100% of people with OCD.
  -> can’t be the full story

Question 8

give the strengths of the biological approach

Answer 8

Strengths:
- scientific basis -> evidence that low serotonin and damage to the basal ganglia correlate with cases of OCD.
-> doesn’t necessarily show a causal relationship.
- Twin studies have shown genetics have some effect on chances of OCD.
- Ethical -> ppl aren’t blamed for their disorders -> just are ill.

Question 9

Explain how OCD can be treated with Drug Therapy

Answer 9

• drug therapy increases serotonin levels using SSRIs (an antidepressant drug that increases availability of serotonin).
• SSRIs prevent reuptake of serotonin in the synoptic cleft.
  -> means more serotonin is available to the next neuron.

Question 10

(+) Explain the strengths of drug therapy to OCD

Answer 10

• Lots of research support -> Thoren et al found the use of an SSRI was significantly better at reducing obsessional thoughts than a placebo.
• Other antidepressants that don’t affect serotonin levels are ineffective at reducing OCD symptons.

Question 11

(-) Explain the weaknesses of drug therapy to OCD

Answer 11

• Up to 50% patients with OCD don’t experience improvements in symptoms when taking SSRIs.
  -> Out of those who do improve -> up to 90% have a relapse when they stop taking them.
• SSRIs must be taken for several weeks before any improvement in symptoms.
• Side effects: Nausea + headaches, increased anxiety at times.
  -> can cause ppl to stop taking medication.

Question 12

give the weaknesses of the bio approach

Answer 12

Weaknesses:
- doesn’t consider the effect of environment, child exps + social influences.
- Ethical concerns with biological therapies -> drugs can produce addiction and may only suppress symptoms rather than cure the disorder.