5. The Biological Approach to OCD

Question 1

What does the Biological model assume

Answer 1

• Assumes psychological disorders are physical illnesses w physical causes.
• In principle, theyre no different from physical illnesses like flu, except they have major psychological symptoms.

Question 2

The 3 Biological explanations for OCD

Answer 2

1. Genetic factors
2. Biochemical factors
3. Neurological factors

Question 3

Biological explanations for OCD: Genetic factors

Answer 3

• Some researchers believe that genetics plays a part in OCD.
• Studies have looked at OCD rates among ppl w relatives who have OCD, to see if having a relative w the disorder significantly increases chances of developing it.

Question 4

Evidence FOR Genetic factors as Biological explanations for OCD

Answer 4

1. Billet et al (1998) did a meta-analysis of twin studies that had been carried out over a long period of time. Found that for identical twins, if one had OCD, then 68% of the time, both twins had it. Compared to 31% for non-identical twins.
2. Pauls et al (2005) - found that 10% of ppl w an immediate relative with OCD also suffered from the disorder. This is compared to around 2% of ppl in the general population.

Question 5

Evidence AGAINST Genetic factors as Biological explanations for OCD

Answer 5

1. No study has found a 100% concordance rate (how likely it is that both ppl in a pair will have a certain characteristic , given one of them does), so genetics cant be the full story in OCD. It’s possible that children imitate the obsessive & compulsive behaviour of their relatives.
2. Concordance rates dont prove that OCD is CAUSED by genetics. It may be that general anxiety is genetic & that going on to develop OCD itself has other contributing factors (biochemical, neurological).

Question 6

Biological explanations for OCD: Biochemical factors

Answer 6

PET scans have shown that levels of the neurotransmitter serotonin are lower in OCD sufferers.

Question 7

Evidence FOR Biochemical factors as Biological explanations for OCD

Answer 7

1. Insel (1991) found that a class of drugs called SSRIs, which increase levels of serotonin, can reduce symptoms of OCD in 50-60% of cases.
2. Zohar et al (1996) also found that SSRI’s alleviated symptoms in 60% of patients w OCD.

Question 8

Evidence AGAINST Biochemical factors as Biological explanations for OCD

Answer 8

1. SSRI’s appear to offer some relief to OCD sufferers. HOWEVER, as it is not true in 100% of cases, there must be more to understanding OCD.
2. The link w serotonin is correlational, so doesnt show cause & effect. May be that decreased serotonin levels are a symptom of OCD, rather than a cause of it.

Question 9

Biological explanations for OCD: Neurological factors

Answer 9

Some research using PET scans has found that abnormality in the basal ganglia within the brain may be linked to OCD.

Question 10

Evidence FOR Neurological factors as Biological explanations for OCD

Answer 10

1. Max et al (1995) found increased rates of OCD in ppl after head injuries that caused brain damage to the basal ganglia.
2. Other researchers have found increased activity in this area during OCD-related thoughts & behaviours.
3. OCD is often found in ppl w other diseases which involve the basal ganglia (eg. Parkinson’s & Huntington’s).

Question 11

Evidence AGAINST Neurological factors as Biological explanations for OCD

Answer 11

1. Aylward et al (1996) didnt find a significant difference in basal ganglia impairment between OCD. patients & controls.
2. Basal ganglia damage HASNT been found in 100% of ppl with OCD, so cannot be the full story.

Question 12

STRENGTHS of Biological explanation of OCD

Answer 12

1. Has a scientific basis in biology - theres evidence that low serotonin & damage to the basal ganglia correlate w cases of OCD, though this doesnt necessarily show a casual relationship.
2. Twin studies have shown that genetics have at least some effect on the likelihood of developing OCD
3. Can be seen as ethical - ppl arent blamed for their disorders; they js have an illness.

Question 13

WEAKNESSES of Biological explanation of OCD

Answer 13

1. Doesnt take into account effect of the environment, family, childhood experiences, or social influences - psychologists taking other approaches consider these factors important.
2. Biological therapies raise ethical concerns - drugs can produce addiction & may only suppress symptoms rather than cure the disorder.

Question 14

How can OCD be treated

Answer 14

Biological therapy

Question 15

What is Biological therapy

Answer 15

• Involves drug therapy.
• Drug treatments usually work by increasing levels of serotonin in the brain using selective serotonin reuptake inhibitors (SSRIs). These are a type of antidepressant drug that increases availability of serotonin.
• SSRIs prevent reuptake of serotonin in the synaptic cleft (gap between 2 neurons). Meaning theres more serotonin available to the next neuron.

Question 16

ADVANTAGES of Biological therapy

Answer 16

• Several researchers have found SSRIs to be effective in treating OCD. Thoren et al (1980) found use of an SSRI was significantly better at reducing obsessional thoughts than a placebo.
• Research has found that using other antidepressants that dont affect serotonin levels is ineffective at reducing OCD symptoms.

Question 17

DISADVANTAGES of Biological therapy

Answer 17

• Up to 50% of patients w OCD dont experience any improvement in their symptoms when taking SSRIs. Out of those that do improve, up to 90% have a relapse when they stop taking them.
• SSRIs must be taken for several weeks before patient experiences an improvement in symptoms.
• Side effects of using these drugs include nausea, headaches & sometimes increased anxiety. Can cause ppl to stop taking the medication.