Mental Health Pharmacology Depression, Anxiety and Bipolar Flashcards
Name clinically recognised states of anxiety:
GAD
Social anxiety disorder
Phobias
Panic disorder
PTSD
OCD
Describe the pathophysiology of anxiety:
Anxiety arises from an abnormal regulation of fear response
Genetic component- runs in families
Amygdala is activated by induction of fear-neuroimaging suggests patients have heightened activity in amygdala circuits
Name the main drugs used for anxiety:
- Antidepressants (SNRIs and SSRIs)
- Benzodiazepines
- Buspirone (5HT1a receptor agonist) (for GAD)
- Gabapentin, pregabalin, valproate
- Atypical antipsychotics
- Propranolol
- Non-pharmacological
Describe antidepressants used in anxiety:
Increase 5HT and NA levels- need 2 weeks to see improvement
e.g escitalopram and paroxetine, venlafaxine, duloxetine
Describe benzodiazepines used in anxiety:
Enhance action of GABA on GABAa receptor containing a2 subunit (G2 and a2 subunits needed)
e.g lorazepam, diazepam, flurazepam- more acute treatment
SEs are sedation, confusion, tolerance and dependence
Describe buspirone used in anxiety:
5HT1A receptor agonist
5HT1Ar can act as inhibitory auto receptors on serotonergic neurones, post synaptic 5HT1Ar are involved in emotional behaviour
Can take few weeks for clinical effect due to desensitisation of 5HT1Ar
Describe how gabapentin, pregabalin and valproate are used in anxiety:
Valproate- Effect NaV channels
Gaba and pregab- effect CaV channels
Anxiolytic properties
Describe how atypical antipsychotics are used in anxiety:
Olanzapine, quetiapine
Effective in GAD and PTSD
Describe how propranolol can be used in anxiety:
BB which can be used for relief of situational anxiety, GAD
Describe the non-pharmacological anxiety treatments:
Counselling
Cognitive therapy
Dietary and lifestyle advice
Describe the pathophysiology of bipolar:
Dendritic spine loss, altered cellular connectivity and neural plasticity
Describe the MoA of lithium in BPD:
Monovalent cation
Mimic role of sodium (move through NaV)-but not pumped out by Na/K ATPase
Thought to accumulate inside cells, cause inhibition of inositol phosphate pathway and inhibition of GSK3 affecting cellular responses
Inhibit GSK3- the phosphorylate important downstream proteins
Name anti epileptics which are used for BPD:
Carbamazepine, valproate, lamotrigine
Describe the use of anti epileptics in BPD:
Affect NaV channels
Blocking action of NaV (inactivated) channels prevents A/P generated
These show use dependance therefore more activity is seen with higher firing rates (e.g in epilepsy)
Describe the MoA of anti epileptics in BPD:
Lamotrigine had a broader MoA, also affects NT release and may have activity on CaV
Due to decrease in neuronal excitation leads to stabilisation in mood
Better SE profile than lithium
Name atypical antipsychotics used in BPD:
Olanzepine
Quetiapine
Risperidone
Aripriprazole
Describe the MoA of atypical antipsychotics in BPD:
Act as antagonists at D2 (GPCR) and 5HT2Ar
Also may have activity at several other GPCRs including a1, H1, 5HT1A and mAChr
Effective against mania
Describe the monoamine theory of depression:
Functional deficit of MAO NTs (5HT and NA) in areas of brain
Arose due to clinical effects on drugs that alleviated symptoms or caused depressive symptoms
Describe the pharmacological evidence for MAO theory which increase mood:
TCA- block MAO uptake
MAOi- prevent degradation of MAO
Tryptophan- increases 5HT synthesis
Describe the pharmacological evidence for MAO theory which decreased mood:
Reserpine- inhibits MAO storage
a-methyltyrosine and methyldopa- inhibits NA synthesis
Describe the findings of the MAO theory:
Inhibition of NA and 5HT NT reuptake equally effective
Direct neurochemical actions are rapid but clinical antidepressants effect takes weeks to develop
2º adaptive changes are thought to be responsible (trophic)
Drugs may have acute effects on cognition- a +ve effect on emotions