monoamine hypothesis dep Flashcards
what does the theory say depression is caused by?
an imbalance in the monoamine neurotransmitters
what kind of imbalance takes place>?
a decrease
what are the the NT involved?
nor-adrenaline, serotonin, dopamine
what was noticed in the 1950s?
drugs that decreased these particular NT caused symptoms similar to depression
what are the characteristics associated with nor-adrenaline?
sleeping, energy, motivation, emotion
characteristics of serotonin>?
mood control, sleeping, hunger
what other job does serotonin do?
regulates Nadrenaline
what happens if there is a low level of serotonin?
low level of Nadrenaline, lack of motivation and pleasure
characteristics of dopamine?
emotion, addiction, pleasure and cog function
what does a decreased amount of dopmaine explain?
diminished interest and lack of pleasure
how many weeks might drugs take to work?
6 weeks
why do drugs not work straight away
due to a neuro-circulatory change in the brain
what type of neuro-circulatory changes occur?
due to the low levels, an up regulation in sensitivity occurs on receptor sites of post synaptic neuron
what happens when the NT suddenly become available through drugs?
a down regulation occurs in sensitivity, causes post synaptic neuron receptors sites to desensitise
what did kilmeck find? (strength)
he compared the brain of 15 dead patients with and without depression, found that there were differences in the part of the brain that produces noradrenaline
showing that ND is involved
what did McNeal and cimbolic find? (strength)
depressives show a lower level of 5HIAA which is produced when serotonin is broken down
what does another biological explanation suggest that goes against this one?
suggests that part of the nervous system is involved and that increased cortisol is associated with depression, incomplete
what doe MRI scans show about the theory?
there have been differences in those with and without depression, specifically a smaller hippo campus, so it is structural as well as biochemical
what is moa-a?
a chemical that removes monoamine nt form the synapse when they are not needed
what does too much moa-a mean?
that too much of the nt are being taken away producing symptoms of depression
