Psych Flashcards
What are the two patterns of depression?
Unipolar: dysthymia (chronic low mood), melancholia (major depression), atypical depression (with other symptoms eg weight gain)
Bipolar: Bipolar Disorder and Cyclothymia
What are the key symptoms of depression?
Persistent sadness or low mood
and/or marked loss of interests or pleasure
What are the additional symptoms beyond the key ones which are pRt of a diagnosis for depression?
Disturbed sleep (decreased or increased compared to usual)
Decreased or increased appetite and/or weight
Fatigue or loss of energy
Agitation or slowing of movements
Poor concentration or indecisiveness
Feelings of worthlessness or excessive or inappropriate guilt
Suicidal thoughts or acts
What circuitry is involved in depression?
Decreased activity: Prefrontal cortex, Hippocampus (reward pathways)
Increased activity: Amygdala, Hypothalamus (HPA) (stress pathways)
What are the 4 theories for depression?
Neurotransmitters– Monoamines: Serotonin (5HT) Noradrenaline. NTs involved in arousal are decreased
Neurohormones - Steroids, HPA axis (Stress, Anxiety)
Immune - inflammatory response has knock on effect on other systems
Circadian - change in sleep wake cycle induces inflammation
Describe the role of 5HT in depression
Main site of production are raphé nuclei in medulla
Acts centrally in multiple areas
Involved in: Mood, agitation, OCD, anxiety, appetite, insomnia, sexual function, nausea and vomitting, GI function
Large interaction between 5HT and NA neurons centrally
Interactions in the brainstem speed activity, Interactions in the cortex slow activity
Describe the role of NA in depression
Main site of NA production in CNS is the Locus Coeruleus
Acts Centrally and peripherally (particulalry ANS transmission)
Multiple Functions: depression, attention, energy homeostastis, agitation, emotions, blood pressure, heart rate, bladder control, motor function
Large interaction between 5HT and NA neurons centrally
Interactions in the brainstem speed activity, Interactions in the cortex slow activity
What structural changes are seen in a depressed brain?
Decreased arborisation
Decreased synapses
Restored by AD/BDNF (brain derived neurotrophic factor)
Overproduction of receptors due to under production of transmitter
How can inflammation lead to depression?
Inflammatory mediators lead to:
Microglia activation, Cell dysfunction, Cell death
Leads to spectrums of disorders
What are treatment options for depression?
Pharmacological: SSRIs, TCAs, MAOI-A, Atypical Antidepressants, e.g. NASSA (Noradrenergic and specific serotonergic antidepressants), NRI (NA re uptake inhibitor)
Cognitive Behavioural Therapy
Transcranial Magnetic Stimulation (TMS)
Electroconvulsive Therapy (ECT)
Describe the placebo effect in depression treatment
30% of patients respond to placebo
Can change neuronal activity levels
Different effects to ADs
Works even if told
Describe electroconvulsive therapy
High frequency activity to cortex - epileptiform activity
Gold standard for severe depression, non responsive to other treatment
50% show improvement
Side effects: Memory loss, Addiction
Describe transcranial magnetic stimulation
Good for severely depressed patients who don’t respond to antidepressants
Significantly less stigma that ECT
Magnetic pulses targeted at: Prefrontal cortex, Limbic system, Increased activity so improve cognition, Fewer side effects
What are Side-effects of SSRIs/5HT modulation?
Slow onset Nausea Sleep disorders Sexual dysfunction Drug interactions may lead to ‘serotonin syndrome’ (hyperthermia, cardiovascular problems, aggression, tremor and rigidity)
What atypical antidepressants can be used for depression?
NRIs work in the same way as SSRIs- Reboxetine
SNRI - combined 5HT and NA reuptake inhibitors - Venlafaxine
5HT partial agonists reduce activity to increase transmitter levels- Buspirone, Trazodone
Name 4 SSRIs that can be used for depression
Fluoxetine
Citalopram
Sertraline
Paroxetine
How can light therapy help in depression?
Light therapy can enhance mood
Sleep pattern disruption depresses mood
Agomelatine: Melatonin agonist, Increases slow-wave sleep, Currently in use for depression
What are the 5 main actions of TCAs?
5HT reuptake blocker NA reuptake blocker α1 adrenoreceptor antagonist H1 receptor antagonist M1 receptor antagonist
What are Side-effects of TCAs?
Accumulation may lead to slowly developing side effects
Sedation due to antihistamine effects
Postural hypotension
Confusion
Visual problems
Cardiac dysrhythmia due to alpha receptor action
Mania
Many drug interactions, from aspirin to alcohol
How are MAOI As used in depression?
Increases NA/5HT levels by inhibiting enzymatic breakdown
Moclobemide - reversible
What are side effects of MAOI A drugs?
Similar to TCAs Many cross drug reactions - DO NOT USE WITH SSRIs/TCAs Postural hypotension Restlessness Convulsions Sleep disorders ‘cheese reaction’
Describe Presynaptic modulation of NA and 5HT by α-adrenoceptors
α-1 receptors act to accelerate
α-2 receptors act as a brake, inhibiting release presynaptically,
α-1 agonists speed transmission up and α-2 antagonists cut the brake cable eg. Mirtazapine - α-2 antagonist
What are Side-effects of adrenoceptor antagonists?
Decreased vascular flow in extremities Postural hypotension Fatigue Bronchoconstriction Cardiac failure Bradycardia Sleep disorders Impotence Depression
How is lithium used?
General mood stabiliser
Acts to reduce G-protein function and inhibits IP pathway signalling,
inhibits various kinases
Suppresses gene function
Increases neurogenesis
Salt used
Slow absorption, modified release form often used
Side effects various depending on intoxication levels