Opioid Dependence and Withdrawal

Opioid Dependence and Withdrawal

A person is said to have physical opioid dependence if they have high 'tolerance' of opioids, meaning they need more of the opioid to get the desired effect. Opioid withdrawal symptoms occur when the substance is stopped. Most patients who seek treatment for opioid addiction also have some degree of physical dependence. However, physical opioid dependence alone is not sufficient to make a diagnosis of addiction. A person can be physically dependent - like a cancer patient might be when prescribed opioids for severe pain - and not be addicted. The term 'addiction' refers to certain behaviors.

What are the Symptoms of Opioid Withdrawal?

Opioid withdrawal can occur in both the addicted patient and the patient who has opioid dependence but is not experiencing total opioid addiction. When an opioid is stopped or the dose is suddenly reduced, both types of patients experience withdrawal symptoms - sweating, chills, muscle and joint pain, nausea, vomiting, diarrhea, restlessness and insomnia. 'Goosebumps', which commonly occur during opioid withdrawal, give rise to the term 'cold turkey'. Fear of these unpleasant and painful opioid withdrawal symptoms makes it difficult for the addict to stop using and begin the recovery process.

Who is Prone to Develop Opioid Dependence?

Although the specific causes vary from person to person, scientists believe that our heredity (our DNA) is the major factor in an individual's susceptibility to the development of the disease of addiction. We also know that psychological factors (feeling stressed, anxious or depressed) and our social environment also play important roles in the development of opioid addiction. The unpleasant effects of opioid withdrawal lead many users to continue abusing prescription or illegal opioids, leading to prolonged dependence.

Opioid abuse has risen dramatically in the United States over the past ten years. The National Institute of Drug Abuse (NIDA) reports that more than 5.2 million Americans misused a prescription painkiller in 2008 for non-medical reasons. Approximately 1 million people in the U.S. are addicted to heroin today. About 1 out of 8 people (13% of the population) who are exposed to a mood-altering substance that can cause an intense euphoric effect (like alcohol, opioids and other drugs of abuse) are prone to develop the behaviors of addiction with repeated use.

What Happens to the Brain in Addiction?

Opioid addiction is a disease of the brain. Repeated use of an opioid leading to opioid dependence causes long-term changes in both the structure (the architecture of the brain) and the way the brain functions (the biochemistry of the brain).

The most important structural or architectural change takes place in the circuitry of the brain - particularly in the wiring of the reward pathway. Our brains are wired to ensure that we will repeat life-sustaining activities - such as drinking water and eating food - by associating those activities with pleasure or reward. Whenever this reward circuit is activated, the brain records that experience making us likely to do it again. Memories that have an intense emotional component (like pleasure) may be permanently 'hard-wired'.

In the person with opioid dependence who is prone to opioid addiction, the excessive stimulation of the reward pathway by an opioid 'tricks' the brain into believing that an opioid is as necessary for survival as food and water. The effect of such a powerful reward motivates people to repeat that behavior again and again, even when it is clearly harmful to do so. This is why drug abuse is something the person prone to opioid addiction can learn to do very, very well.

Chemical changes also take place in the brain as it tries to adapt to the excessive stimulation of the reward pathway. During opioid dependence and opioid addiction, the brain tries t