the medical model Flashcards
what are the three causes of mental illness?
biochemical, genetic, brain abnormality
what are some biomedical treatments?
advances in neuroscience in the 20th century and increasing influence of drug companies mean that psychology is more medical than ever.
what does the medical model see disorders as?
the result of biological malfunctions or disruptions
biochemical explanations
our brain cells transmit information through electrical impulses that allow us to think, feel and act. at the end of each brain cell there is a synapse. neurotransmitters must cross the synapse to transfer information. different neurotransmitters are used to regulate different mental processes. believes that mental illness symptoms are caused by abnormal neurotransmitter levels or actions.
what neurotransmitters are believed to be involved in depression?
the monoamines- serotonin, noradrenaline, and dopamine
what does dopamine do?
regulates mood
what does noradrenaline do?
it is linked to activity levels
what does serotonin do?
controls the activity of the other neurotransmitters
what is the first monoamine hypothesis of depression?
stressful events will lead to a reduction in serotonin levels, which causes a failure to regulate dopamine and noradrenaline functions. this disrupts mood and activity levels.
what is the second monoamine hypothesis of depression?
the disruption of monoamines is caused by abnormally high levels of an enzyme which breaks down monoamines. this reduces their action and disrupts information being passed around the brain.
genetic explanations
a person’s genotype comes directly from their mother and father. genes contain the instructions for producing physical structures, including the brain and chemicals such as neurotransmitters and enzymes. it is likely that genes exert an influence on psychological characteristics, including mental illness, by influencing physical structures such as the CNS.
is mental illness purely down to genetic explanations?
it is unlikely, however it appears that some people are more vulnerable than others to developing mental health problems as a result of their genetic makeup.
what mental illnesses are genetically vulnerable?
common depression is only moderately affected by genes, however vulnerability to schizophrenia is more affected to genetic variations
what is the strongest predictor of depression?
stressful life events, rather than genetics
what forms does the serotonin transporter gene come in?
long/long, long/short, short/short
which serotonin transporter form is more vulnerable to depression?
short/short, as it is thought this form leads to inefficient serotonin production. this makes people less resilient to stress and more prone to depression.
brain abnormality explanations
the human brain is an extremely complex system. the structure/function can be associated with mental illness. if structures are a different size, this means that electrical activity may be abnormal in particular regions. CNS does not function normally when suffering from certain conditions.
is there evidence for brain abnormality in depression?
the frontal lobe (thinking) is thought to play a part, as its volume was significantly lower in depressed patients, and has an abnormal draw on blood flow
gottesman (2010) disorders in offspring with two psychiatrically ill patients, method
a national-register based cohort study in denmark looking at the risk of schizophrenia/bipolar in people born between 1968-97
gottesman (2010) disorders in offspring with two psychiatrically ill patients, schizophrenia results
risk of mental illness was much greater for offspring of two parents with a diagnosis. risk of schizophrenia was 27.3% in offspring with both parents having a schizophrenia diagnosis, and 7% with only one parent admitted.
gottesman (2010) disorders in offspring with two psychiatrically ill patients, bipolar results
risk of bipolar was 24.9% in offspring of two bipolar parents, 4.4% for one parents, and 0.48% for neither.
what does gottesman’s (2010) study suggest?
it suggests a genetic explanation for some mental illnesses
what do biological treatments assume?
the physical makeup of a person has to be altered in some way
which biological treatment is the most common?
drug therapy, as it is quicker than talking therapies such as CBT, but has side effects such as antidepressants increasing suicidal thoughts
what are other biological treatments?
electroconvulsive therapy ECT- passes an electric shock through anaesthetised brain. a quick fix for relieving depression whilst waiting for drug therapy to become effective. can cause confusion/memory loss.
how do older antidepressants MAOIs work?
prevents the breakdown of serotonin, noradrenaline, and dopamine so levels of all the monoamines build up
how do older antidepressants tricyclics work?
prevents serotonin and noradrenaline being absorbed after crossing a synapse, which increases their levels
issues with older antidepressants
old-fashioned so can have side effects as they interfere with a number of neurotransmitters
how do newer antidepressants SSRIs work?
stops serotonin being broken down and reabsorbed after crossing a synapse.
how do newer antidepressants NRIs work?
stops noradrenaline being broken down and reabsorbed after crossing a synapse helpful for patients who are feeling inactive.
why is it important to have a lot of different antidepressants?
because they all work in slightly different ways and patients will respond differently to them
benefits of biological treatment
most drug treatments seem effective in relieving symptoms and allowing people to manage day-to-day life; only requires patients to take the drug- no lifestyle change; relieves symptoms whilst the patient prepares for another type of therapy, or can be used alongside another therapy
limitations of biological treatment
do not work for everybody- people may respond differently and side effects can be problematic; drugs are unlikely to provide a long term cure unless there is a clear biological cause- symptoms may return.
bias in publication regarding drug treatments
81% of studies with significant findings were published, compared with 68% of studies reporting non-significant findings. this bias makes drug treatments appear more effective than they really are.
