Li et al (2013)

• Li et al (2013) - Investigating the relationship between chronic heroin use and changes to specific brain areas
• The experimental group has 14 heroin addicted males with an average age of 35 years. All were from a drug rehabilitation center in China and has used heroin for an average of 89 months. They were tested and found clean for any drugs bar nicotine, all right handed and none had any psychiatric disorders.
• The participants each did a 40 Minuit session in a fMRI scanner where they were exposed to 24 drug related images and 24 neutral images each shown for 2 seconds in a random order.
• They found that there was significantly different activation in areas of the posterior cingulate cortex and areas associated with the reward system in the heroin group compared to the control group.
• Heroin addicts reported cravings for heroin following the cue inducing images.
• They found stronger connectivity between the posterior cingulate cortex and the bilateral insula (controls emotional states and subsequent behaviours) and between the posterior cingulate cortex and the bilateral dorsal striatum (associated with drug seeking behaviour) in the heroin group.
• They found a positive correlation between the degree of connectivity and length of heroin use.
• Activity in the posterior cingulate cortex was increased when ex-addicts were shown drug related cues.
• The posterior cingulate cortex is related to visual orientation, reward processing and is sensitive to unpredictable rewards.
• Heroin use alters the functionality and connectivity of the brain to reinforce addictive thinking, cravings and drug seeking behaviours which becomes abnormally associated with reward.
• The posterior cingulate cortex could be used as an indicator for the extent of brain damage cause by drug use.
• The sample used cannot be generalized females or other cultures.
• This study has ethical concerns as exposing ex-addicts to drug related images could cause a relapse.
• Using brain scanning techniques makes isolating activity difficult as other brain areas will also be active.