issues in mental health - the medical model

the biochemical explanation of depression

• Serotonin is a neuro transmitter. When a sense is stimulated, a message will be sent along the nervous

  system. The message will go from one nerve cell to another until it reaches the appropriate area in the central

  nervous system.

• The nervous system is made up of thousands of nerve cells (neurons). These nerve cells are not physically

  connected to each other. Instead, there are synaptic clefts (i.e. gaps) between nerve cells and these gaps

  need to be crossed for a message to pass from one pre-synaptic) nerve cell to another post-synaptic) nerve

  cell.

• if levels of serotonin are low then the serotonin molecules may be absorbed back into the pre-

  synaptic nerve cell too soon (to await further stimulation). This would mean that the message may not get

  passed effectively across the gap.

the biochemical explanation of schizophrenia

• could be related to high levels of dopamine within the nervous system, this causes an excess of dopamine reaching the post-synaptic nerve cells.

• dopamine is a neurotransmitter

treatment aims

focusing on restoring normal live;s of neurotransmitter action:

• depression - blocking re-uptake of serotonin to ensure there is enough serotonin available for messages to get carried along the nervous system.

• schizophrenia - blocking receptors in post-synaptic nerve cells to prevent an overload of dopamine reaching the post-synaptic nerve cell.

genetic explanation of MH - from parents

• certain disorders could be passed from parents to children through genetic transmission.

• Gottesman et al: the increased risk if children have two parents with either bipolar disorder or schizophrenia compared to those with one parent or no parents with these disorders. However, as concordance rates are not 100% (i.e. children don’t always have the same disorders that their parents have), there have to be environmental or individual difference effects that make some people more prone to diagnoses of mental illness than others.

• they found that if one twin had schizophrenia then there was a 58% chance of an identical mono-zygotic) twin having it; however, if the twins

  were not identical (i.e. they were dizygotic), then there was only a 12% chance of a twin having it. This study suggests that there is a strong genetic component to schizophrenia, but it also suggests that occurrences of schizophrenia cannot be explained by genetics alone.

genetic explanation of MH - evolutionary theory

• There are certain traits that may in the past have enabled some people to survive while other people without these traits will have died. It is suggested that we have inherited traits that have a beneficial effect on our chances of survival.

• a possible explanation for phobias as people with a fear of spiders, snakes, heights, deep water, etc., might have had an evolutionary advantage that enabled them to survive and reproduce while people without these phobias may have died before they got a chance to reproduce.

• Ohman: gave participants electric shocks at the same time that they saw pictures of either snakes, houses, or human faces. It was easier to condition a fear response to the snakes than it was to either the houses or human faces, suggesting an inherited biological predisposition to fear snakes more.

treatment for genetic explanations

Embryo manipulation to reduce the inheritance of genetic disorders by using genetic material from three parents is in the early stages of research.

brain abnormality

the symptoms of mental health unless are explained in terms of natural differences in either the structure or function of certain brain regions.

Weinberger - brain abnormality

by doing MRI scans of twins who were identical but who were not concordant for

schizophrenia (i.e. one had it but the other didn’t) – that there were differences between the two groups in the prefrontal cortex and the hippocampal volume.

brain abnormality as the cause of depression

• patients with depression can show a smaller hippocampal volume that people not experiencing depression

• people with depression have experienced stress. This has led to the release of cortisol. There is evidence that cortisol can destroy hippocampal cells. This would mean that these hippocampal cells can then not respond to stimulation in the way that they normally might. If so, this would reduce the effect of serotonin in the body.

• sheline - in a study of elderly women whose depression was in remission – that the hippocampus was smaller in these women than it was in other women of the same age.

brain abnormality - treatment

drug therapy or surgery if tumours are a cause.

Gottesman et al

aim - to investigate in a large sample the probability of a child being diagnosed with a mental disorder if either or both of their parents have the disorder.

sample - Anyone in Denmark aged between 10 years and 52 years in January 2007 and with a clear link to their biological parents. This meant a sample of almost 2.7 million people and their parents being studied.

procedure - Using data from the Psychiatric Central Register, Gottesman et al identified four groups of people:

 Both parents admitted to a psychiatric hospital with diagnoses of schizophrenia, bipolar disorder, or depression

 One parent admitted to a psychiatric hospital with a diagnosis of schizophrenia, bipolar disorder, or depression

 Neither parent admitted with a diagnosis of a disorder

 The ‘general public’ (with no data available on whether they had parents admitted with psychiatric illnesses or not)

findings - schizophrenia + bipolar

Both parents admitted with the disorder 27.3% 24.9%

One parent admitted with the disorder 7% 4.4%

Neither parent admitted with the disorder 0.86% 0.48%

General population admitted with the disorder 1.12% 0.63%

SSRI’s

block the re-uptake of serotonin

biological treatment - brain stimulation (ECT)

electro-convulsive therapy - this is where a patient has electrodes placed on their temples; an electric shock is then passed into their brain.

the aim is to trigger an epileptic seizure in an attempt to ‘jump start’ the entire brain and relieve the symptoms of a mental health disorder - it is administered under anaesthetic.