Tag Archives: visual analogue scale

Pain Sensitivity in Opiate Addicts

I recently read the article “Abnormal pain response in pain-sensitive opiate addicts after prolonged abstinence predicts increased drug craving” written by Ren Zhen-Yu.  This article is a great foundation for what I want to write my research proposal on.

In the article, the different intensities of cravings of opiate addicts was related with how much pain was felt.  Overall, the opiate addicts  in this study showed a shorter tolerance for pain than control subjects, which is one of the reasons I have decided to use alcoholics instead of opiate addicts in my study.  Opiate addicts can show either an increased tolerance to pain or a decreased tolerance to pain, depending on what stage of addiction the individual is in-development, maintenance, withdrawal periods, and periods of abstinence.  This could be because opiates have a specific receptor in the brain, since our bodies can actually produce certain opiates (endorphins).  Also, opiates such as morphine are used to treat pain directly.  Additionally, people who are at risk for opiate addiction might already be partially intolerant of pain.  They might choose to take opiates to relieve their pain.  Our bodies cannot naturally produce alcohol, and alcohol does not directly affect pain receptors, so I feel like alcoholism will be a better substance disorder for me to test than opiate addiction.

I like the descriptions of the participants that were involved in the study.  The opiate addicted participants had to be four months sober, could not be on any other psychoactive drugs except nicotine (so cigarettes are okay), any prescribed medicine, any medication for physical or mental disorders, and could not have a pain condition.  The control patients had to have no history of substance abuse, pain conditions, serious physical or mental disorders, and not be on medication.  To ensure this, a urine sample was taken to test for drugs.  They were collected through word of mouth and advertisement.  I feel like this will be a good model for me to follow.

A Cold pressor test (CPT) was used to test for tolerance to pain and pain intensity (sensory aspect) and distress (affective/emotional aspect).  I really like this quote that was used to describe the difference between pain intensity and distress. “To understand the difference between pain intensity and distress, think of listening to music on a radio. As I turn the volume up, I can ask you how loud the music is or I can ask you how pleasant or unpleasant the music is to listen to.  The intensity of pain is like the loudness of music. How pleasant or unpleasant the music is depends on how much you like or dislike the music, and the distress of pain depends on how much you dislike the sensation.”  These levels were measure using separate visual analogue scales VAS 0-100, 0 being “not at all intense” or “not at all unpleasant” and 100 being “the most intense pain imaginable” or “the most unpleasant pain imaginable.”  Again, this seems like a really good model for me to follow.