Depression Flashcards
How is depression diagnosed?
Either Via DSM-V or ICD-10
How would you diagnose based on DSM-V?
There are 2 core symptoms - low mood, and loss of interest
for diagnosis, the patient must exhibit 5-9 symptoms which includes one of the core symptoms.
Symptoms should be present for at least 2 weeks and be of sufficient severity for most of each day.
What is the proposed etiology of depression and how does that link to 1st line treatments?
Etiology is based on amine deficiency theory of depression, suggesting deficiency in the amines, particularly 5-HT (serotonin).
Treatments are based on this i.e selective serotonin reuptake inhibitors target the SERT transporter, Inhibits the reuptake of serotonin from the synaptic cleft so more serotonin is available to bind to 5-HT receptors and reduce symptoms.
At roughly what threshold of depression would you initiate drug treatment?
Persistent subthreshold/mild to moderate with inadequate response to initial interventions/moderate/severe
Common low intensity psychological interventions for subthreshold and mild
individual guided self help based CBT 12 weeks
computerised CBT
group physical activity programmes
High intensity psychological interventions
Individual CBT 16-20 sessions over 3-4 months
interpersonal therapy ^same
Behavioural couples therapy
Why are MOAIs not commonly used now?
Many side effects, and interactions with certain foods e.g. cheese can be life threatening
1st line drug treatment in depression
SSRIs e.g. sertraline, fluoxetine, paroxetine, citalopram, escitalopram
Side effects of SSRIs and why?
Nausea/vomiting - stimulation of 5-HT3 receptor in hypothalamus and brainstem- chemoreceptor trigger zone
Diarrhoea - 5-HT3 AND 5-HT4 stimulation
CNS e.g. anxiety - 5-HT2A, 5-HT2C
Sexual dysfunction 5HT3
Insomnia
Dosage of sertraline
50mg, then increased if needed by 50mg weekly up to 200mg/day maximum
Is suicidal ideation common in SSRIS?
What is it common with?
No
TCAs
Interactions of SSRIs?
Increased risk of bleeding esp in elderly and people on NSAIDS/drugs that affect clotting e.g. aspirin, warfarin.
- consider PPI to protect gastric mucosa
NOTE: fluoxetine and fluvoxamine have higher risk of interactions than other ssris
Which antidepressant causes weight gain?
Mirtazapine
Tricyclic antidepressants e.g. imipramine, amitryptylline
Which antidepressants are toxic in overdose?
TCAs
Which anti. depressant have anti muscarinic side effects e.g. dry mouth, consipation, urinary retention, blurred vision?
TCAs as they target mAchRs (non selective)
Which anti depressants have sedation and drowsiness?
TCAs as target H1 receptors
Mitrazapine
Which anti depressants have greater cardiovascular risk?
Venlafaxine
TCAs
Citalopram and escitalopram SSRIs cause QT interval prolongation
What drug is better if QT prolongation?
Sertraline
Which drugs have a higher tendency to lower seizure threshold?
TCAs
Some SSRIs e.g. citalopram (use sertraline in epilepsy)
Counselling or advice for patients treated for depression?
- anti depressants are not addictive
- full effect takes time ~2-4 weeks
- must continue after remission for at least 6 mo
- There is a risk of discontinuation symptoms esp if stop abruptly or have drugs with shorter half life e.g. venlafaxine, paroxetine. Doses should be reduced slowly tapered down
S/E and how to manage
How are anti depressants initiated and followed up generally?
Start on lowest dose effective as an anti-depressant. Monitoring after 2 weeks, see regularly every 2-4 weeks in first 3 months then at longer intervals if response is good. Improvement should be after 2-4 weeks.
What is serotonin syndrome?
Symptoms after either an increased SSRI dose or combo of drugs that enhance serotonin e.g. Tramadol, fentanyl, lithium, ondansetron, buspirone, st. johns wort.
- flu like symptoms, diarrhoea, sweating, confusion, convulsions
Stop offending drugs
Treat the symptoms e.g. cyproheptadine is an antihistamine which blocks the effect of the serotonin receptors
what is the Interaction of MOAIs e.g. with food?
Irreversibly binds to the MAO enzyme disrupting its function. Tyramine is a potent releaser of noradrenaline and can increase BP. Normally tyramine doesn’t accumulate as it is broken down by MAO-A. Any foods high in tyramine e.g. cheese can cause hypertensive crisis as not enough broken down.
What are the treatment aims in depression
Prevent suicide
Provide symptomatic therapy
Identifying possible causes (primary)
investigate social domestic and financial circumstances
initiate long term therapy to prevent relapse/recurrence
Why are SSRIS preferred?
less side effects More specific Less toxic in overdose no anticholinergic effects less sedating than TCAs Less suicidal ideation
3 things you need to tell a patient when they start SSRIs
- take at least 4 weeks to start having an effect
- take for at least 6months-1 year (continue taking even when feel better for at least 6 months)
- risk of discontinuation symptoms, shouldn’t stop abruptly - taper down, and they’re not addictive
