Depression Flashcards
What is usually the physiological cause of depression?
Deficit of noradrenaline or serotonin
How is noradrenaline synthesised?
From dopamine by dopamine-beta hydroxylase
How is noradrenaline removed from the synapse and how is this relevant to depression treatment?
Normally reuptake by noradrenergic receptors in presynaptic membrane
Some antidepressants inhibit this action
What is controlled by the noradrenaline pathways?
Alertness
Arousal
Sensory perception
Motor tone
How is serotonin synthesised?
Tryptophan to 5-hydroxytryptophan by tryptophan hydroxylase
5-hydroxytryptophan to 5-hydroxytryptamine by aromatic amin acid decarboxylase
How is serotonin in the synapse controlled?
Reuptake by serotonin transporter in presynaptic membrane
Serotonin also activates 5-HT1a autoreceptor which regulates synthesis and release
What is controlled by the serotonin pathways?
Sleep Food intake Thermoregulation Sexual behaviour Pain Motor tone
When would depression be considered?
If low feelings last longer than 2 weeks and start to interfere with daily life
What is considered as unipolar depression?
Major depressive disorder
Dysthymia
Seasonal affective disorder
Postnatal depression
What is bipolar?
Alternating periods of mania and depression
How do SSRIs work and why do they take a few weeks to work?
Inhibit reuptake of serotonin from synapse
Autoreceptor reduces serotonin production as a result but eventually is down regulated and serotonin release is restored
What are the side effects of SSRIs?
GI side effect
Hyponatraemia
Bleeding risk
QT prolongation
What may be the advantage of using SSRIs?
Less concerns with overdose, sedation and cardiac problems
Give some examples of SSRIs
Sertraline Citalopram Fluoxetine Escitalopram Paroxetine Fluroxamine
How do SNRIs work and why are they not first line?
Inhibit reuptake of both serotonin and noradrenaline
Problems with tolerability