The Monoamine Hypothesis

Question 1

What are monoamines?

Answer 1

A group of neurotransmitters containing amino acid

Question 2

Which monoamines is the hypothesis concerned with?

Answer 2

Noradrenaline, Seretonin, Dopamine

Question 3

What suggests that monoamines are involved?

Answer 3

Antidepressents raise the levels of them and in some cases this solves depression

Question 4

How is seretonin said to be involved?

Answer 4

It is carried across the synapse to the post synaptic neuron by a transporter. Changes in the gene encoding of this transporter could lead to low seretonin

Question 5

What causes the changes in the seretonin transporters?

Answer 5

Stress

Question 6

Where are seretonin recepetors found?

Answer 6

In the central nervous system cells

Question 7

What is the role of seretonin?

Answer 7

To regulate other neurotransmitters

Question 8

What happens if seretonin doesn’t regulate neurotransmitters?

Answer 8

Erractic brain functioning and faulty thinking patterns occur

Question 9

How does erratic brain functioning and faulty thinking patterns explain depression?

Answer 9

Many people with depression have inappropriate guilt and feelings of unnecessary worthlessness which is a result of faulty thinking patterns

Question 10

What can low levels of seretonin produce?

Answer 10

Low levels of noradrenaline

Question 11

What is noradrenaline required for?

Answer 11

To show alertness, energy, anxiety and attention to life

Question 12

How do low levels of noradrenaline link to depression?

Answer 12

Depressed people often suffer from hypersomnia where they sleep excessively due to lack of energy, low noradrenaline can reduce energy

Question 13

What do some antidepressents work to do?

Answer 13

Some increase noradrenaline, some increase dopamine

Question 14

What is the role of dopamine?

Answer 14

It is related to the ability to show attention and motivation, pleasure and reward

Question 15

What do low levels of dopamine explain in terms of depression?

Answer 15

why some people have a markedly diminished interest in activities as they don’t have dopamine to give them the feeling of pleasure

Question 16

How does Versiani et al (1999) support the monoamine hypothesis?

Answer 16

A double blind trial of noradrenaline reuptake inhibitors (NRIs) and a placebo found an increase in the mood of depressed patients with NRIs, supports that an increase of noradrenaline is needed

Question 17

Why can drug research be problematic?

Answer 17

Because drugs containing monoamines might help treat depression but it doesn’t mean they caused it, it could be that environmental factors made NTs fall low

Question 18

What is an opposing biological explanation?

Answer 18

That increased levels of cortisol in parts of the nervous system is implicated in depression suggesting the monoamine hypothesis is incorrect

Question 19

What did Klimeck et al (1997) find when he compared the locus coeruleus of 15 dead patients with major depression with 15 who didn’t suffer?

Answer 19

The locus coeruleus is responsible for producing noradrenaline and they found differences in structure suggesting that this affects the production of NTs

Question 20

What did McNeal and Cimbolic (1986) find?

Answer 20

That patients suffering from depression show lower levels of 5-H1AA than the non depressed, this is a chemical found when seretonin is broken down suggesting low levels

Question 21

How does opipramol oppose the hypothesis?

Answer 21

It is a drug used to treat depression that has an action unrelated to monoamine neurotransmitters and suggests other factors are involved

Question 22

What have MRI scans shown that oppose the hypothesis?

Answer 22

That there are physical differences in the brain in people with depression comapred to those without, these may cause depression e.g smaller hippocampus