Long-Term Marijuana Use Linked to Changes in Brain's Reward System

(Live Science, June 10) People who use marijuana for many years tend to react more favorably to pictures of marijuana than of other things they also prefer, such as their favorite food. The research found that people who used the drug for 12 years tended to have more brain activity in the reward system when shown images of marijuana paraphernalia than something else they also liked. The study shows that marijuana rewires the brain's natural circuitry and causes the brain to tend towards marijuana products and association. It may be a sign that recreational use is moving towards a problem and addiction. READ MORE.