psychopathology - biological approach to explaining OCD

Question 1

neurochemical explanation - AO1

Answer 1

• suggets OCD is due to imbalance in neurotransmitters
• specifically low serotonin levels (1 mark)
• serotonin = maintains stabe mood
• mutation in SERT gene leads to serotonin being recycled too quickly back to pre-synaptic neuron
• so post-synaptic neuron is not activated (2 marks)
• low levels of serotonin = cause anxiety
• associated with obsessions in OCD (3 marks)

Question 2

genetic explanation - AO1
intro

Answer 2

• genetic approach suggests OCD is due to physical factors in body
• runs in families
• genetic predisposition to OCD is inherited (1 MARK)
• genetic explanation suggests OCD is due to inheritance to one or more maladaptive genes e.g. SERT GENES
  (2 MARKS)

Question 3

genetic explanation - AO1
twin studies

Answer 3

• genetic explanation suggets closer genetic link = more at risk to inheriting OCD
• twin studies: monozygotic twins = 87% concordance
• dizygotic twins = 47% concordance
• Carey and Gottsman 1981
  (3 MARKS)

Question 4

genetic explanation - AO1
candidate genes

Answer 4

• candidate genes = vulnerable to developing OCD
• called COMT and SERT gene
  (4 MARKS)

Question 5

genetic explanation - AO1
SERT genes

Answer 5

• SERT genes = transportation of serotonin
• mutated SERT gene = decrease in serotonin
• increases anxiety and OCD symptoms
  (5 MARKS)

Question 6

genetic explanation - AO1
COMT genes

Answer 6

• COMT genes = regulation of dopamine in brain
• one form of COMT gene is more common in OCD individuals
• causes increase in dopamine levels
• leading to compulsions
  (6 MARKS)

Question 7

neural approach - AO1

Answer 7

• argues that OCD is due to differences in size/functioning of specific brain areas (1 MARK)
• OCD linked to basal ganglia
• basal ganglia = psychomotor functions
• hypersensitivity of basal ganglia = repetitive movements (2 MARKS)
• helps explain compulsions in OCD (3 MARKS)

Question 8

Criticism - AO3
biological reductionism

can be used for all biological explanations of OCD

Answer 8

P - can be criticised for being biologically reductionist

E - reduces complex human behaviour
- down to simple basic units
- e.g. SERT genes/neurotransmitter imbalance/neuro anatomy

E - neglects holistic approach which takes into account persons culture/social context
- e.g. certain religious groups have higher prevalence of OCD due to regular cleansing ritual before prayer

L - lowers validity
- does not allow us to understand behaviour in context

Question 8

Strength - AO3
objective and empirical methods

USE FOR NEURAL/GENETIC APPROACH ONLY

Answer 8

P - strength of biological explanation
- uses objective (factual) and empirical (observable) techniques

E - e.g. gene mapping and brain scans

E - helps identify specific genes e.g. SERT genes
- and areas of brain linked to OCD e.g. basal ganglia hypersensitivity

L - increases internal validity
- raising scientific status of psych

Question 9

Strength - AO3
practical applications

USE FOR NEUROCHEMICAL/GENETIC APPROACH ONLY

Answer 9

P - strength of this explanation
- practical applications

E - principle of explanation: OCD due to mutation in SERT gene leading to low levels of serotonin
- led to drug treatment development

E - Selective serotonin reuptake inhibitors (SSRI’s)
- increase serotonin levels in brain
- reducing anxiety
- relieving OCD symptoms

L - important part of applied psych
- used to better lives of OCD individuals