Addiction

Addiction – to gambling, to alcohol, to food, to any compulsive human behavior without regard to consequences – ruins lives.

But how does addiction manifest in the brain? Researchers at the Center for BrainHealth led by Dr. Francesca Filbey are hoping to reveal the interactions between genetic and environmental factors that lead to addiction. Dr. Filbey and her team are studying the effects of addiction across the lifespan with the hope of discovering predictors for individuals that might be at risk.

Currently, Center for BrainHealth researchers are looking at brain responses to reward and punishment in non-using adolescents aged 12 to 17. The goal of studying responses in a younger, non-using population is to determine those who are most at risk for addiction later in life and develop strategies for earlier intervention to prevent addiction.

Previous research conducted by Dr. Filbey, funded by the National Institutes of Health, studied neurobiological mechanisms and genetic predispositions in adults 18 to 55 who were already vulnerable to the cycle of addiction. The cycle of addiction includes three phases: initiation, maintenance, and relapse. In the initiation phase, addicts receive positive reinforcement through drug use (i.e., reward, pleasure). During the maintenance phase, research has shown that users continue drug use in order to prevent a negative consequence from happening (i.e., withdrawal); therefore, the drug provides a negative reinforcement. How a brain responds depends on where an individual is in the cycle of addiction.

Scientists saw how drugs and alcohol, in essence, hijack the brain so that its reward system stops responding to natural rewards such as food when more potent stimuli – like the buzz from powerful intoxicants – are introduced into the system. The findings suggests that being able to avoid harm, such as withdrawal symptoms, may be just as rewarding for marijuana users as the consumption of marijuana itself, and may be the mechanism that maintains marijuana abuse. 

Advances in imaging and genetic analyses have shown that there are individuals who are at higher risk for addiction due to a hypo-responsive reward system, meaning they require more stimulation in order to experience the same amount of pleasure as those not at risk. Unfortunately, within this group the hypo-responsive reward network is also accompanied by an inefficient control system which makes keeping the urges in check extremely difficult despite all potential negative consequences that could result.

Below are some general behaviors that may signal an addiction:

• Changes in school performance (falling grades, skipping school, tardiness)
• Changes in peer group
• Breaking rules at home, at school or in the community
• Extreme mood swings
• Sudden increases or decreases in activity levels
• Withdrawal from others
• Changes in physical appearance (weight loss, lack of personal hygiene)
• Changes in eating or sleeping habits
• Lack of motivation or interest in hobbies