Clin- Monoamine Hypothesis Flashcards
What is the background of monoamine hypothesis?
- 1950s- monoamine oxidising inhibitors used for people with TB
- Patients who took these drugs became remarkably euphoric and this was one of the first indicators that NT were implicated in depression
What did Schildkraut (1965) say about Noradrenaline?
Too much leads to mania but too little leads to depression.
What is Noradrenaline?
the body’s initial stress response.
increases heart rate and blood pressure
released in a branch of the nervous system
What is serotonin?
serotonin in the brain regulates anxiety, happiness and mood.
What happens when you have low Noradrenaline?
Lethargy, lack of pleasure, problems with concentration
What happens when you have low Serotonin?
the Noradrenaline is permitted to decrease, which can cause depression.
What happens when you have low dopamine?
Anxiety, fatigue, mood swings.
What did Prange (1974) say?
A deficit in serotonin permits the symptoms of depression
Describe Wender and Klein’s study (1981)
administered dugs to rats which lower levels of noradrenaline; the behaviour of the rats became sluggish and inactive.
What did Lemonick (1997) find?
They found that drugs used to treat depression increased levels of both noradrenalin and serotonin.
Thase et al (2002)
Depressed patients had increased levels of noradrenaline, which is the opposite of what monoamine hypothesis predicts.
If this theory is true, what would happen if you take drugs to increase serotonin levels?
Drugs treatments that concentrate on raising serotonin levels (SSRI’s) do improve the depressed mood in the majority of patients
• Newer anti-depressants (like Effexor) are actually targeted at both serotonin and noradrenaline, and are even more effective in treating depression
What did Diksic et al (1997) find about gender differences in depression?
He found that men make 52% more serotonin than women. This could make men far less prone to depression than women.
What are some criticisms of this theory?
Not all depressives show reduced levels of these neurochemicals. These patients would not benefit from drug treatments. This implies there are other factors involved.
Even following recovery from depression the deficits in serotonin and noradrenalin levels still remain.
What is therapeutic delay?
it often takes 4-6 weeks for depressives to see any improvements in their symptoms.
