A Drug to cure fear? Could this really work...and where does fear come from?
/
· Phobias, panic attacks and PTSD extremely common
o 29% of American adults suffer anxiety at some point in their lives
· What is fear?
o Fear is a chain reaction in the brain that starts with a stressful stimulus
§ Causes the release of chemicals that cause:
· racing heart
· fast breathing
· energized muscles
· also known as the fight-or-flight response
o Stimulus could be a spider, a knife at your throat, an auditorium full of people waiting for you to speak or the sudden, load noise
o The process of creating fear begins with a scary stimulus and ends with the fight-or-flight response.
· Fear and anxiety stems from emotional memory
o Emotional memory: associations you have between various stimuli and experiences and your emotional response to them.
o Because of emotional memory fear is learned
o Previously harmless situation can predict danger
· Current treatment for phobias
o Exposure therapy: repeated exposure to feared object or frightening memory in a safe setting
§ Done to create new safe memory in the brain alongside the bad memory
§ Fear is suppressed
§ If patient is re-traumatized or re-exposed to original experience, his old fear will return worse than before
§ Can be difficult to relive scarring memories
§ Limitations of exposure therapy
§ Only works for ~50% of PTSD cases
· New Research in Curing Fear
o New research from University of Amsterdam suggests that it may be possible to change and perhaps ERASE certain types of emotional memories
o Past research
§ Memories are uniquely vulnerable to alteration at two points
· when we first lay them down
· when we retrieve them
o Study published last month suggests emotional fear response in healthy people with arachnophobia, erased
o published in the journal Biological Psychiatry
§ compared three groups made up of 45 subjects in total
· One group was exposed to a tarantula in a glass jar for two minutes then given a beta-blocker (propranolol)
· One was exposed to the tarantula and given a placebo
· One was just given propranolol without being shown the spider, to rule out the possibility that propranolol by itself could decrease spider fear
§ subjects’ anxiety when they were shown the spider the first time, then again three months later, and finally after a year
o Results:
§ Those given propranolol alone and those who got the placebo had no improvement in their anxiety
§ Those exposed to the spider and given the drug were able to touch the tarantula within days and, by three months, many felt comfortable holding the spider with their bare hands
§ Their fear did not return even at the end of one year
o Mechanism:
§ Propranolol blocks the effects of norepinephrine in the brain
§ Chemical similar to adrenaline, enhances learning
· Blocking it disrupts the way a memory is put back in storage after it is retrieved — a process called reconsolidation
· By reactivating the fear, the fear memory was made susceptible to the influence of propranolol