An introduction to the psychopharmacology of mood disorders Flashcards
What is the function of a modulatory neuron?
Changes the effects of other neurotransmitters or second messenger systems
How do mood disorder drugs act?
Altering brain function:
- change neurotransmitter function
- mimic neurotransmitters (agonist)
- block receptors (antagonist)
What are agonist drugs?
Drugs that mimic neurotransmitters
What are antagonist drugs?
Which block receptors
What is the main excitatory neurotransmitter?
Glutamate
What is the main inhibitory neurotransmitter?
GABA
What are the monoamine neurotransmitters?
- Dopamine
- Serotonin (5-HT)
- Noradrenaline
What are the targets of monoamine drugs in mood disorders?
> Serotonin system
- SSRI and SNRI antidepressants
- second generation antipsychotics -> 5HT receptor actions
> Dopamine system
- second generation antipsychotics - D2 and D3 blockade
> Noradrenaline system
- SNRIs (Venlafaxine, Duloxetine)
What is the target of Ketamine and its action?
- Targets glutamate system
- Blocks NMDA Glu receptor
- Shows promising efficacy in improving mood in patients with depression
What is the target of benzodiazepines and valproate?
GABA system
What is the target of the mood stabilisers lithium, valproate and carbamazepine?
Second messenger systems
What are the main discoveries in the history of the psychopharmacology of mood disorders?
> 1940s: Electroconvulsive therapy
> 1950s: lithium
> 1960s: First generation antidepressants: MAOIs, MARIs
> 1980s: Anticonvulsants (Carbamazepine, Lamotrigine, Valproate)
> 1990s: Second generation anti-depressants
> 2000s: Next-generation antipsychotics (Quetiapine, Olanzapine, Clozapine, Asenapine, Aripiprazole)
Why is serotonin of interest in mood disorders?
> Lowering serotonin levels -> induces depression
> Increasing serotonin levels -> can produce manic symptoms
> SSRI antidepressants and atypical antipsychotics all work in part by changing serotonin systems in brain
How does a normal serotonin system function?
> 5hT cell bodies are located in the caudal raphe nuclei (midbrain)
> Serotonin pathways have projections to the limbic system and subgenual cingulate
What are the important serotonin receptors related to mood disorders?
- 5-HT 2
- 5-HT 1A
What is the action of selective serotonin re-uptake inhibitors (SSRIs) in the synapse?
Inhibit action of 5-HT re-uptake transporter
-> increases synaptic serotonin levels