I&D: Clinical Psychology

Question 1

Biolochemical explanations I&D: the dopamine hypothesis (nature vs nurture, holistic vs reductionist, free-will vs determinism)

Answer 1

Nature vs nurture:
- there is wealth of research evidence to support the role of nature in schizophrenia.
- In one study, rats were injected with amphetamines over a 3-week period. This increase dopamine activity (Tenn et al., 2003).
- The rats showed a range of schizophrenic-like behaviours, inc social withdrawal.
- symptoms were alleviated when they were given drugs to block their D1 dopamine receptors.
- This supports the role of biological factors (nature) in schizophrenia but also underlines the importance of environmental factors (nurture) e.g. drug taking.
- Despite that, Dépatie and Lal (2001) found that apomorphine, a dopamine agonist (iniates a physiological response when combined w a receptor), does not worsen symptoms in ppl with a schizophrenia diagnosis and neither does it trigger symptoms in those that do not.
- this highlighted the role of nurture in predicting the impact of biological factors.

Reductionism vs holism:
- A limitation of the dopamine hypothesis is that they are highly reductionist. The idea that a single neurotransmitter is responsible for schizophrenia is no longer accepted.
- clozapine (blocks dopamine and serotonin receptors) are often more effective than drugs that only block dopamine receptors (e.g. chlorpromazine)
- also, the efficacy of newer drugs, e.g glutamate agonists, suggests that an exploration of the interactions between a range of neurotransmitters might be more useful than studies that focus on single neurotransmitters.
- Taking a holistic approach and recognising how **neurotransmitter levels are affected by life experiences and how we interpret them is also critical.
- Various lifestyle choices including mindfulness, sleep, exercise and diet can affect our neurochemistry and it is therefore important to recognise how the prognosis of conditions like schizophrenia can be affected by numerous individual and situational factors, due to their impact on our biology

Determinism vs free will:

• The biological explanation of schizophrenia is deterministic; it suggests that the workings of the brain are responsible for the symptoms of schizophrenia.
• Research using PET brain scans demonstrates that ppl w schizophrenia have decreased binding on their prefrontal D1 dopamine receptors in comparison with ppl without schizophrenia (Okubo et al. 1997).
• there were also significant correlations between D1 binding, severity of negative symptoms and performance on the Wisconsin Card Sorting Test (a measure of cognitive ability).
  This supports dopamine deficiency as an explanation of negative and cognitive symptoms and the role of biological determinism.

Question 2

Biochemical explanations I&D: genetic explanations (reductionism vs holism, nature vs nurture, methodology)

Answer 2

Methodology:

• One issue in family, twin and adoption studies is sampling.
• samples are often relatively small and not representative of the whole population
• This is because there are not very many ppl who are part of a set of twins where at least 1 of the twins has schizophrenia
• However, Hilker et al 2017 recruited a vast sample of 30k twin pairs from 2 nationwide registers, ensuring a representative sample and therefore, his study can be more generalisable
• Some twin and adoption studies are longitudinal which increases the validity as diagnoses and changes in behaviour over time can be more observable
• This makes them more useful than a study where we only look at the ppts at one point in time

Nature vs nurture:
- the role of genetics (nature) in schizophrenia is supported by various twin studies, but the validity of these findings is questionable.
- It is assumed that MZ twin pairs living in the same household will be exposed to environmental factors that are similar to pairs of DZ twins, which is unlikely.
- As MZ twins are always an identical gender, look identical, share similar temperaments than DZ twins, MZ twins are likely to be parented more similarly than DZ twins.
- Therefore, that the degree of both genetic and environmental similarity differs between MZ and DZ twins, making it impossible to infer that the higher concordance rate for schizophrenia in MZ twins is due to them sharing 100% of their DNA.
- This implies that nurture might play a more important role in schizophrenia.

Reductionism vs holism

• A further weakness is this explanation is reductionist; taking this perspective may limit awareness of the range of treatment options.
• While our genome may impact our cognition and experiences, research suggests that it is possible to train ourselves to interpret our thoughts in more beneficial ways.
• it demonstrates that nurture can override nature when environmental experiences are carefully curated.

Question 3

Psychological explanations I&D: cognitive (individual vs situational explanations, reductionism vs holism, nomothetic vs idiographic)

Answer 3

Individual vs situational factors:

• Cognitive theory explains individual differences in mental health by highlighting the differences in the ways people process information.
• however, it cannot explain the episodic nature of schizophrenia.
• ppl do not suffer from symptoms all the time, despite processing information in the same way.
• It is possible that situational factors, such as situational stressors increase cognitive load to a point where they cannot cope, and this triggers a psychotic breakdown.
• This shows that schizophrenia may be influenced by both individual and situational explanations
  – cognitive deficits predispose people to psychotic breaks, but situational factors are required for the symptoms to manifest.

Reductionism vs holism:

• it is unclear why some people have these cognitive deficits in the first place and this is a weakness of a reductionist approach.
• Cognitive theories suggest that symptoms develop due to faulty thinking strategies but do not explain why some people think in different ways compared to others.
• This means the cognitive theories provide a partial account of schizophrenia.

Idiographic vs nomothetic:
- One issue is that research into both biological and cognitive explanations of schizophrenia tends to take a nomothetic approach.
- This means the studies are often experimental in nature and compare groups of people with and without schizophrenia to find differences between them that might explain why some people have the condition and others do not.
- findings are then generalised to larger populations.
- however, it fails to take account of individual differences between people with schizophrenia (a highly heterogeneous disorder), which can manifest itself in very different ways.
- Taking a more idiographic approach through the use of case studies may reveal key factors that correlate with more positive long-term outcomes.
- the trauma-informed approach advocated by Johnstone (2018)** focuses on listening to people’s stories regarding their life experiences and how they interpreted them.
- this approach help practitioners to understand the context of the person’s symptoms (e.g. as a reaction to traumatic experiences) and provides idiographic support for cognitive explanations of psychotic symptoms.