Substance addiction is a leading cause of lost work productivity, health problems, financial distress, incarceration, domestic violence, and death. It is hard to find anyone that has not been touched in some way by addiction, whether directly or indirectly. Just because a person uses alcohol or even illegal drugs does not mean that he or she is addicted to them. Addiction does not care about a person's age, gender, social status, or race.

Substance addiction is defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as tolerance, increased use of a drug(s) or alcohol, and withdrawal. Withdrawal symptoms can range from physical symptoms like nausea, diarrhea, sweating, insomnia, and flu-like symptoms to psychological symptoms such as depression, anxiety, irritability, and restlessness. Too much time spent obtaining, using, and withdrawing from the drug are also symptoms of addiction. An important marker for substance addiction is a person continuing to use the drug(s) and alcohol regardless of negative consequences. Many addicts will use the justification that they can stop anytime and/or that they have stopped using for some length of time yet they return to use. While stopping is good, it is the return to use that hints of addiction. A very important question to ask regarding substance addiction and drug use is whether or not the person using the drug(s) or alcohol keeps using or going back to use after they have realized that the drug caused them problems in the past.

For people who reach a pivotal point in their substance addiction their body can give out on them. This will manifest physically by a person who has a sudden loss of tolerance. Sometimes the body gets so saturated and depleted that it can no longer process the substances. This results in a person using less of the drug or alcohol and it having the same effect. So, if a person used to be able to drink a six pack of beer and get a slight buzz, but now they drink it and get drunk this signifies a drop of tolerance and possibly liver damage.

It is important to remember that addiction is a chronic, debilitating, and deadly brain disease that does not have anything to do with morality or will power. Addiction is highly stigmatized by society and causes a lot of damage both to individuals and those around the addict. The term substance addiction is used interchangeably with chemical dependency, addiction, and alcoholism. A person crosses the line from drug abuse to addiction when the choice to use is no longer present. For example, a person can use heroin on a weekend, abuse it and have devastating consequences from it, but when this use goes to several days, increased use of heroin, and then withdrawal symptoms upon stopping the use, it crosses the line into addiction.

Substance addiction is hard to treat and tends to be a chronic relapsing disease. Traditional treatment centers are starting to change, but the change is slow. As more people realize that addiction is literally a neurological disorder because of the physiological changes that occur in a person's brain when they become addicted then the attitude toward treatment will drastically change.