Biological Model
Area Mental Health (Applied)
Files
Notes
1) Biological Explanations
Outline and evaluate the dopamine explanation for Schizophrenia
An explanation for Sz is the idea that an overactive dopamine system in
schizophrenic people produce symptoms like hallucinations. We know this
because a drug called chlorpromazine that can block dopamine receptors
can be used to reduce the positive symptoms of Sz, thus suggesting that an
excess in dopamine could be responsible for creating schizophrenic
symptoms. We also know this because autopsies of schizophrenic brains
show higher number of dopamine receptors than non-schizophrenic brains
(Falkai), which means more dopamine receptors allow more dopamine to
bind, thus large amount of dopamine produces schizophrenic symptoms.
The dopamine explanation might be valid in that: Falkai’s research of
autopsies of schizophrenic brains
The dopamine explanation might not be valid in that we can’t claim cause
and effect for the biological explanations from the success of biological
treatments. Advocates for the dopamine explanation claim that drugs that
block dopamine receptors like chlorpromazine reduce schizophrenic
symptoms, thus Sz must be caused by high levels of dopamine. However,
this is too reductionist as it doesn’t take into account other factors that could
have influenced the likelihood of having Sz like social context, so this is like
claiming a bullet wound is caused by a skin puncture while it could have been
caused by being shot with a gun, just because a biological treatment
successfully deals with it (Cohen). Therefore there might be some
environmental factors that can explain the high dopamine levels in
schizophrenic brains.
Outline and evaluate the monoamine explanation for Depression
Biological Model 1
, The monoamine explanation supports the idea that people with depression
have an abnormally high levels of the enzyme MAOA which breaks down
monoamines and so preventing it from sending messages between neurons.
This then results in low mood and reduced activity levels.
This explanation might be valid in that drug treatments for depression like
SSRIs and TCAs which work by increasing monoamine levels have been
found to be effective in 50% to 65% of people, and they are also more
effective than placebos, thus suggesting a link between depression
symptoms and low levels of monoamines.
This explanation might not be valid in that it might be an oversimplified
explanation for depression, as when healthy volunteers take the medication
that reduces monoamine levels, they experienced no depressive symptoms
(Delgado)
Outline and evaluate a genetic explanation for Schizophrenia
The genetic explanation for Sz is that it is partially genetics. We know this
because Gottesman’s study showed a strong positive correlation between
genetic similarity and concordance rates for Sz. For example, the
concordance rates for Sz is 48% in monozygotic twins and 17% for dizygotic
twins - in which the shared genetic material between them are 100% and
50% respectively.
The genetic explanation for Sz is high in reliability because the link found
between genetic relatedness and concordance rates for Sz is reliable. We
know this because Gottesman’s adoptive and twin studies found that a higher
degree of genetic relatedness tend to concide with higher concordance rates,
thus further supporting the idea that higher genetic relatedness correlate with
higher concordance rates for Sz.
The genetic explanation for Sz is low in constructive validity in that it’s too
reductionist. This is because the shared genetic material between
monozygotic twins is 100% while the concordance rates for Sz is only 48%,
which means that even though genes increase the likelihood of developing
Sz - they are not the only cause. Therefore it’s reductionist as Sz can’t be
completely explained by genetics since something else besides genetic
relatedness must have mattered too.
Outline and evaluate how brain abnormality could explain Depression
Biological Model 2
Area Mental Health (Applied)
Files
Notes
1) Biological Explanations
Outline and evaluate the dopamine explanation for Schizophrenia
An explanation for Sz is the idea that an overactive dopamine system in
schizophrenic people produce symptoms like hallucinations. We know this
because a drug called chlorpromazine that can block dopamine receptors
can be used to reduce the positive symptoms of Sz, thus suggesting that an
excess in dopamine could be responsible for creating schizophrenic
symptoms. We also know this because autopsies of schizophrenic brains
show higher number of dopamine receptors than non-schizophrenic brains
(Falkai), which means more dopamine receptors allow more dopamine to
bind, thus large amount of dopamine produces schizophrenic symptoms.
The dopamine explanation might be valid in that: Falkai’s research of
autopsies of schizophrenic brains
The dopamine explanation might not be valid in that we can’t claim cause
and effect for the biological explanations from the success of biological
treatments. Advocates for the dopamine explanation claim that drugs that
block dopamine receptors like chlorpromazine reduce schizophrenic
symptoms, thus Sz must be caused by high levels of dopamine. However,
this is too reductionist as it doesn’t take into account other factors that could
have influenced the likelihood of having Sz like social context, so this is like
claiming a bullet wound is caused by a skin puncture while it could have been
caused by being shot with a gun, just because a biological treatment
successfully deals with it (Cohen). Therefore there might be some
environmental factors that can explain the high dopamine levels in
schizophrenic brains.
Outline and evaluate the monoamine explanation for Depression
Biological Model 1
, The monoamine explanation supports the idea that people with depression
have an abnormally high levels of the enzyme MAOA which breaks down
monoamines and so preventing it from sending messages between neurons.
This then results in low mood and reduced activity levels.
This explanation might be valid in that drug treatments for depression like
SSRIs and TCAs which work by increasing monoamine levels have been
found to be effective in 50% to 65% of people, and they are also more
effective than placebos, thus suggesting a link between depression
symptoms and low levels of monoamines.
This explanation might not be valid in that it might be an oversimplified
explanation for depression, as when healthy volunteers take the medication
that reduces monoamine levels, they experienced no depressive symptoms
(Delgado)
Outline and evaluate a genetic explanation for Schizophrenia
The genetic explanation for Sz is that it is partially genetics. We know this
because Gottesman’s study showed a strong positive correlation between
genetic similarity and concordance rates for Sz. For example, the
concordance rates for Sz is 48% in monozygotic twins and 17% for dizygotic
twins - in which the shared genetic material between them are 100% and
50% respectively.
The genetic explanation for Sz is high in reliability because the link found
between genetic relatedness and concordance rates for Sz is reliable. We
know this because Gottesman’s adoptive and twin studies found that a higher
degree of genetic relatedness tend to concide with higher concordance rates,
thus further supporting the idea that higher genetic relatedness correlate with
higher concordance rates for Sz.
The genetic explanation for Sz is low in constructive validity in that it’s too
reductionist. This is because the shared genetic material between
monozygotic twins is 100% while the concordance rates for Sz is only 48%,
which means that even though genes increase the likelihood of developing
Sz - they are not the only cause. Therefore it’s reductionist as Sz can’t be
completely explained by genetics since something else besides genetic
relatedness must have mattered too.
Outline and evaluate how brain abnormality could explain Depression
Biological Model 2
