Kim Flashcards
What are the six adjunct therapies for anxiety disorders and PTSD that we learned about?
Four are pharmacological, one is techy and one is behavioural
Pharmacological
- D-Cycloserine (DCS)
- Proponol/noradrenaline
- Cortisol
- Oxytocin
Techy
5. Direct brain stimulation TMS or Transcranial Direct Current Stimulation TDCS
Behavioural
6. Exercise
Why are we interested in D-Cycloserine (DCS) in the context of anxiety disorders and PTSD?
Because D-Cycloserine (CDS) has been shown to facilitate fear extinction in rats, and so has been studied in humans.
What was the main human trial of D-Cycloserine (DCS)?
PILOT double blind RCT
Gave it to humans during an exposure therapy for heights (using a virtual floor) and it improved response to therapy
5 sessions with DCS better than 5 sessions with placebo
How has D-Cycloserine been applied to other anxiety disorders?
It’s a mixed bag
Good results =
- Social anxiety
- Panic disorder
- OCD
Negative results =
- OCD
- Social anxiety
Null results =
- PTSD
What did the meta-analysis of D-Cycloserine say?
It was a COCHRANE meta-analysis, baby
- 22 DCS RCTs across different anxiety disorders
- some individual trials showed an effect, the overall picture was null
What even is D-Cycloserine?
A partial NMDA receptor agonist
Minimal side effects
What is the mechanistic significance of D-Cycloserine (DCS) being a partial NDMA receptor agonist?
Because fear extinction is mediated by the NMDA receptors
What might explain the way different anxiety disorders respond to D-Cycloserine (DCS) differently?
Different neurobiological mechanisms at the level of the NDMA receptor, about which we know little (animal models are too coarse)
Why do we even care about cortisol when thinking about anxiety and fear stuff
Cos cortisol aids memory consolidation, and what they want its to consolidate the memory of the fear EXTINCTION, thus inhibiting the underlying memory associated with the conditioned stimulus
Dysregulation of cortisol is found in anxiety disorders and PTSD
What is the evidence about all this cortisol stuff
CORTISOL AND EXPOSURE THERAPY
Need to properly write up
A recent clinical trial administered hydrocortisone during exposure therapy in PTSD, and found greater PTSD symptom reduction with hydrocortisone relative to placebo, greater retention in treatment with the hydrocortisone group, and an association between reduction in PTSD symptoms and glucocorticoid receptor sensitivity (Yehuda et al., 2015).
What is the evidence about all this cortisol stuff
CORTISOL AND FEAR EXTINCTION
Need to properly write up
There is evidence that enhanced glucocorticoids/cortisol can facilitate fear extinction learning and recall in both animals and humans (DeQuervain et al., 2008; Benz et al., 2013)
A recent RCT revealed greater reduction in spider fear with administration of hydrocortisone prior to exposure therapy relative to placebo (Soravia et al., 2014).
Cortisol moderated the relationship between PTSD symptoms and fear extinction –
High cortisol reactivity was associated with lower PTSD symptom severity as fear extinction learning improved
Low cortisol reactivity was associated with higher PTSD symptom severity as fear extinction learning improved
WTF is Yohimbine?
A substance that increases the level of noradrenaline that is released
What is the name of the substance that increases the level of noradrenaline?
Yohimbine
What does Yohimbine do around fear stuff in RATS
- conditioning
- extinction
- extinction retrieval
Boosts the lot
What does Propranolol do around fear stuff in RATS
- conditioning
- extinction
- extinction retrieval
impedes the lot
