Depression + Anxiety Flashcards
What is the DSM 5 diagnostic criteria for major depressive episode?
A) more than 5 symptoms on most days for 2 weeks (that present change from precious functioning)
- depressed mood or loss of interest must e present
- weight gain/loss, insomnia/hypersomnia, psychomotor agitation/retardation, fatigue, feelings of worthlessness/guilt, decreased concentration, suicidal ideation
B) symptoms must cause significant clinical impairment in functioning
C) episode not attributable to direct physiological effects of substance or medication
D) not better explained by presence of schizophrenia, delusional disorder or any other psychotic disorder
E) no history of manic or hypomanic episode
Explain the mechanism of action of antidepressants.
Increase NT in synaptic cleft by:
- Blocking degradation of NT - MAOI
- Blocking NT reuptake - SSRI, TCA, SNRI
Name three examples of drugs that are in the TCA dug class.
Amitriptyline
Nortriptyline
Imipramine
Name three examples of drugs that are in the SSRI drug class.
Fluoxetine
Citalopram
Sertraline
Paroxetine
Escitalopram
Name two examples of drugs that are in the SNRI drug class.
Venlafaxine
Duloxetine
Name two examples of drugs that are in the MAOi drug class.
Selegiline
Phenelzine
Patients who are on MAO inhibitors should be warned about consuming aged foods in large quantities, why is this the case?
Aged foods like cheese and wine contain tyramine, which is broken down by MAO. If patient is on a MAO inhibitor, the tyramine will accumulate in the synapse, thereby increasing it effect.
Causes release of norepinephrine, resulting in a hypertension crisis.
What is the primary mechanism of action of TCAs?
Inhibition of reuptake of monoamines.
- TCAs block the reuptake of serotonin and norepinephrine into presynaptic nerve terminals by inhibiting their respective transports (SERT and NET).
- leads to an increase in the synaptic concentration, enhancing their signalling and improving mood.
Describe the secondary effects of TCAs on other receptors.
- Histamine H1 receptor blockade (drowsiness and weight gain)
- Muscarinic receptor blockade (anticholinergic sides effects - dry mouth, constipation, blurred vision, urinary retention, cognitive impairment)
- Alpha 1 receptor blockade (orthostatic hypotension)
- Sodium channel blockade (cardiotoxicity in overdose - arrhythmias)
List the adverse effects of TCA use.
Tachycardia
Arrhythmias
Urinary retention
Blurred vision
Nausea
Drowsiness
Weight gain
Dry mouth
Constipation
List the adverse effects of SSRI use.
Insomnia
Anxiety
Sexual dysfunction
Drug interaction
Nausea
Describe the mechanism of action of SSRIs.
They bind to and inhibit the SERT on the presynaptic neuron. This prevents the reuptake of serotonin from the synaptic cleft and as a result, serotonin levels in the synaptic cleft increase, allowing for prolonged activation of post synaptic serotonin receptors.
Does not interfere with other NTs. Selectivity reduced the likelihood of side effects compared to TCAs.
What is the risk of taking “strong” pain tablets like tramadol when on SSRIs?
Pain medication inhibits the reuptake of serotonin, therefore serious side effect when combined with SSRIs. Increases serotonin activity - serotonin syndrome.
What are the symptoms present in serotonin syndrome?
Mydriasis
Agitation
Diaphoresis
Tachycardia
Autonomic instability - often hypertensive
Increased bowel sounds - possibly diarrhoea
Clonus (esp in lower extremities)
Tremor (esp in lower extremities)
Hyperflexia (esp in lower extremities)
What is treatment of choice in major depressive disorder in pregnancy and breastfeeding women?
1st line - Cognitive behavioural therapy
2nd line (safe) - citalopram, escitalopram, sertraline