AEFFECTIVE DISORDERS: DEPRESSION Flashcards
Which group is most likely to be affected by depression
women, more specifically black and mixed race women
depression
- broad and heterogenous diagnosis
- Central to its depressed mood and/or loss of pleasure in most activities
- symptoms should be present for at least 2 weeks at sufficient severity for most of every day
diagnostic systems for depression
ICD-10/11 and the DSM-5 classification system
severity is determined by both the number and severity of symptoms
bipolar I disorder
where a person has had at least one manic episode and periods of significant depression, each usually lasting for an extended period
bipolar II disorder
the person has never had a manic episode, but has had at least one hypomanic episode and at least one period of significant depression
cyclothymia
similar to bipolar but with lower extremes
euthymia
period without mood disturbances
aetiology of bipolar disorder
strong genetic component - inheritability
usually diagnosed in late teens
use of lithium in bipolar disorder
- used to calm manic patients and prophylactically as a mood stabiliser
- results observed relatively quick and are considered safe (no overdose risk)
lithium potential moa
- modulation of glutamate, GABA and DA neurotransmission
- inhibition of inositol triphosphate formation
- interference of cAMP formation
- accumulation of Li+ in cell leading to sustained depolarisation
side effects of lithium
long half-life leads to common side effects such as nausea, thirst, tremor and mental confusion
key symptoms for major depressive disorder (MDD)
- persistent sadness or low mood
- loss of interests or pleasure
- fatigue or low energy
associated symptoms of major depressive disorder (MDD)
- disturbed sleep
- poor concentration or indecisiveness
- low self-confidence
- poor or increased appetite
- suicidal thoughts or acts
- agitation or slowing of movements
- guilt or self-blame
degrees of depression
not depressed - <4
mild depression - 4 symptoms
moderate depression - 5 or 6
severe depression - >7 symptoms with or without psychotic symptoms
monoamine hypothesis
- suggests that depression results from deficient monoamine transmission
- monoamine oxidase inhibitor developed for TB, elevated the mood of the treated patients
- thus the Amine hypothesis proposes that depression occurs due to decreased levels of amines (NA, 5-HT and DA) in the CNS
problems with the monoamine hypothesis
- drug action is relatively fast (hours) but relief of symptoms takes longer (weeks)
- antidepressants have differing mode of action but work similarly on symptoms
noradrenergic system neuromodulation in the brain
locus coeruleus
serotenergic system neuromodulation in the brain
raphe nucleus
dopaminergic system neuromodulation in the brain
ventral tegmental area (VTA) and substantial nigra (SN)
antidepressant groups
selective serotonin reuptake inhibitors (SSRIs)
serotonin noradrenaline reuptake inhibitors (SNRIs)
monoamine oxidase inhibitors (MAOIs)
tricyclic antidepressants (TCAs)
psychotherapies for depression
- behavioural therapy
- interpersonal therapy
- group therapy
- cognitive behavioural therapy (CBT)
- mindfulness based cognitive therapy (MBCT)
brain stimulation methods in depression
- electroconvulsive therapy (ECT)
- vagus nerve stimulation (VNS)
- transcranial magnetic stimulation (TMS)
- deep brain stimulation (DBS)
benefits and risks of SSRIs
- better tolerated and reduced risk of overdose
- increased risk of bleeding esp. in older pts/those taking anticoagulants
- less sedating and fewer antimuscarinic and cardiotoxic effect than TCAs
- sertraline safe with cardio issues (do not use citalopram)
- fluoxetine, fluvoxamine and paroxetine have higher drug interactions than other SSRIs
benefits and risks of TCAs
- similar to SSRIs but adverse effects
- antimuscarinic side effects - dry mouth, urinary retention, blurred vision etc.
- cardiotoxicity
- sedation
- weight gain
- risk of overdose
- increased risk of coma/seizure, and potentially fatal cardiac arrhythmia/arrest
benefits and risks of MAOIs
- should only be prescribed by specialists
- hepatotoxicity (isocarboxazid and phenelzine)
- dangerous interactions with some food and drugs > hypertensive crisis - ‘cheese reaction’
use of electroconvulsive shock treatment (ECT)
- even most severe bouts of depression are usually responsive to ECT
- still used to day in cases of very severe depression with a high risk of suicide, where there has been no response to drug treatments
first line for depression
sertraline + CBT/IPT
how long do you continue on an antidepressant before switching to a different kind
6-9 months (assess efficacy after 1-4 weeks)
novel treatments: ketamine and esketamine
- single dose of NMDA inhibitors can cause a rapid (next day) antidepressant effect in pts with MDD
- primarily used in treatment resistant depression (resistant to 2 or more antidepressants)
SSRI drugs
fluoxetine
citalopram
escitalopram
paroxetine
sertraline
SNRI drugs
duloxetine
venlafaxine
TCA drugs
amitriptyline
clomipramine
dosulepin
imipramine
lofepramine
nortitriptyline
MAOI drugs
tranylcypromine
phenelzine
isocarboxazid
