Most scientists now consider addiction a brain disease: a condition caused by persistent changes to brain structure and function. Using drugs repeatedly over time changes brain structure and function in fundamental and long lasting ways that can persist long after the individual stops using them. After a certain amount of a drug is consumed, and that amount is different for everyone, it is as if a switch in the brain is flipped from normal to addict.

Addiction is defined as uncontrollable, compulsive drug craving, seeking and use even in the face of negative health and social consequences. Very few people are able to return to occasional use after becoming addicted.

But, as we know, not everyone who uses drugs becomes addicted. Some people can become addicted more easily and quickly than others. Estimates are that 50 to 70 percent of these differences in susceptibility to addiction are genetic. Still, the author reminds that genes do not doom one to become an addict.

What understanding addiction as a brain disease means Many people believe that drug addiction is a failure of will. Research contradicts this. However, this does not mean the addict is simply a hapless victim, nor does it absolve the addict of responsibility for his or her behavior. But it does explain why an addict cannot stop using by sheer force of will alone.

The paper draws parallels between addiction and other chronic reoccurring illnesses such as asthma, diabetes and hypertension and reminds us that voluntary behaviors (here the decision to try drugs) are involved in other illnesses. Hypertension, cardiovascular disease, diabetes and some forms of cancer are heavily influenced by the individual eating, exercise, smoking and other behaviors.

How do you treat addiction? Research finds that the best forms of treatment heal the entire individual, combining medication, behavioral therapy, social services and rehabilitation.

Another crucial finding on drug treatment is that it does not need to be completely voluntary to work. In fact, studies suggest that increased pressure to stay in treatment -- whether from the legal system, or from family members or employers -- increases the amount of time patients remain in treatment and improves their treatment outcomes.

What you can do to help a person with drug addiction 1. Understand that while a person who is addicted to drugs made the choice to try the drug, they did not choose to become addicted. An addicted person brain is functioning abnormally and their drug use is out of their control. They need and deserve the same medical treatment as anyone else with a chronic illness would receive.

2. Find them a treatment program that treats all of their individual problems together, such as drug addiction, behavioral issues, mental illness and/or life skills.

3. Since treatment does not have to be voluntary to work, consider involving the justice system, employer or other

Read the full report Addiction is a Brain Disease by Alan I. Leshner