bio explanation of depression

Question 1

what are monoamines?

Answer 1

group of neurotransmitters containing amino acids

Question 2

examples of monoamines

Answer 2

serotonin, noradrenaline, dopamine

Question 3

what is the biological explanation of depression?

Answer 3

depression is caused by a decrease in monoamine neutrotransmitters in the CNS, particularly serotonin as it regulates other neurotransmitters

Question 4

what are low levels of monoamine acitivity caused by?

Answer 4

• reputake
• monoamine oxydase

Question 5

low levels of monoamine acitivty caused by reuptake

Answer 5

the reuptake mechanism recaptures the monoamines before they reach the receptor sites so their message don’t get to the next neuron

Question 6

low levels of monoamine acitivty caused by monoamine oxydase

Answer 6

too much monoamine oxidase is produced (enzyme which breaks down and removes monoamines from the synapse) so monoamines do not reach receptor sites to pass message on as they have been broken down into smaller components

Question 7

supporting evidence for the monoamine hypothesis

Answer 7

Versiani (1999) used a double-blind trial of noradrenaline reuptake inhibitors (NRIs) and a placebo drug and found significant mood improvement in NRI group compared to placebo.

T: monoamine hypothesis is a valid way of explaining unipolar depression

Question 8

contradicting evidence for the monoamine hypothesis

Answer 8

Trivedi (2006) found only one third of people using the SSRI Citalopram were in complete remission (decrease in symptoms)

T: not a valid way of explaining unipolar depr. as there are other expl.

Question 9

Evidence has high scientific status - monoamine hypothesis

Answer 9

E: Royal College of Psychiatrists
50-60% of people treated with antidepressants showed improvement compared to 25-30% of people treated with a placebo.

T: internally valid

Question 10

Contradicting scientific evidence - monoamine hypothesis

Answer 10

P - contradicting scientific evidence with reliability
E - MRI scans show physical differences in the brain in people with depression compared to those without - hippocampus 10-15% smaller. Hippocampus is linked to mood and memory.
T - Therefore lowers validity of explanations ion

Question 11

monoamine hypothesis - application - useful society

Answer 11

P - Application to real life which can be useful for society

E - Has led to the development of more effective drugs tailored to subpopulations of people with depression. Fluoxetine targets serotonin whereas Duloxetine targets both serotonin and noradrenaline levels.

T - this can improve people’s quality of life

Question 12

monoamine hypothesis - false assumption that if bio treatment effective, target = cause

Answer 12

P - False assumption that if a biological treatment is effective in reducing symptoms, the target of that treatment (low levels of serotonin) must be the cause of the disorder.

E - This is not necessarily the case - just because sero levels can be treated with medication, this doesn’t mean they are the cause of depression because there could be psychological causes such as stress/ maladaptive thoughts.

T - The treatment aetiology fallacy suggests neurotransmitters may not be the cause.

Question 13

monoamine hypothesis - construct validity

Answer 13

P - Neurotransmitter explanation can explain why antidepressants can take 2-6 weeks to improve symptoms.

E - They increase sero/norad levels in synapse so postsynaptic receptors take time to downregulate (fewer produced) to compensate for greater stimulation.

T - has Construct validity

Question 14

monoamine hypothesis - reductionist

Answer 14

P: biologically reductionist

E: reduce the complex experience of depression down to monoamines, ignoring how the individuals thoughts/cognition could influence depression

T: less valid