Why doesn't everyone who takes opioids become addicted?

Why doesn't everyone who takes opioids become addicted?

about 10% of those prescribed opioid medications become addicted

By Dr.Fourkan Ali

Summary: 

Pain can offset the euphoria

 otherwise produced by the opioids. Without a net excess of induced euphoria, the 

reward system is not triggered

 and the 

addiction process never begins

. 

Physical dependence and tolerance do form

, but both are easily remedied in the absence of addiction.

Addiction medications maintain tolerance and physical dependence

 while allowing for the 

behavioral changes necessary for addiction remission

. Although it's possible for someone to become addicted to the buprenorphine, it is uncommon.

Why Some Get Addicted and Not Others

Not everyone who takes opioids will become addicted. In fact most people who take opioid medication do not become addicted, even some on high doses for long periods of time. Although many will develop tolerance and physical dependence, only a minority develop the compulsive and uncontrollable behaviors of addiction. Part of understanding this is knowing the profound difference between physical dependence and addiction. Understanding why people don't become addicted helps us in understanding addiction itself.

Reward System Stimulation

We learned earlier that addiction forms as a result of repeated stimulation of the brain's reward system. The brain interprets the flood of opioids as an indication of a positive experience necessary for survival. The unnatural level of opioid stimulation exceeds what the brain is equipped to handle and the result alters the brain and produces persistent strong cravings long after opioids are stopped.

However, if a patient is in pain, the opioids merely offset feelings of pain, instead of causing intense euphoria. While pain is present, and while dosed to match, the unnaturally high levels of euphoria are never created to trigger the reward cycle. Without the repeated high euphoria, associations are not created and the compulsive condition does not form.

Tolerance, Physical Dependence, Addiction

Other processes such as the development of tolerance and physical dependence occur just as they would with those on the path to addiction. Dose requirements rise to maintain a constant level of pain suppression. Eventually, tolerance rises to the point of physical dependence whereas the patient would experience withdrawal if they were to stop the opioids abruptly or sharply decrease their dose. Withdrawal does not indicate addiction.

Chronic pain patients who manage to take enough opioids to reduce pain but not enough to induce a net high euphoric response, generally don't develop addiction but do developed tolerance and physical dependence. For them, a taper off of the opioids when no longer needed reduces withdrawal symptoms to low levels with little if any longer term symptoms.

Contrast this with a person who has developed tolerance and physical dependence along with addiction. They can resolve the physical dependence with a slow taper as well, if they are able to control the cravings. However unlike the non-addicted person, after the taper, the brain adaptations associated with addiction will produce lingering symptoms of anxiety, depression, lethargy and cravings which could last for months. These post acute-withdrawal symptoms often lead patients to relapse. This is why detox treatment are notoriously unsuccessful. It may also explain why some say that they are "in recovery" rather than" recovered", as fighting the symptoms becomes a never-ending experience. However, coping with the brain changes of addiction may not be the only choice. Reversing the brain adaptations may greatly reduce their ability to cause long-term symptoms, and that is what evidence-based medication assisted treatment with buprenorphine is all about.

Genetics and Environment Can Contribute

Many factors can disrupt the balance of the level of euphoria with the level of pain, placing the patient at greater risk for the development of addiction. Continuing to take the medication after the pain has passed is one example. Genetic factors also can make one person more susceptible to addiction than others. Stress, depression, anxiety and environmental facts can all contribute to the decision to take more medication than is warranted by the pain.

Buprenorphine is Different

Evidence-based addiction treatment consists of reversing, to the extent possible, the brain adaptation of addiction, before tapering off opioids completely. This is where treatment medications such as buprenorphine can help. Although it is possible for some to develop cravings and uncontrollable compulsions toward buprenorphine, generally patients maintain control of their buprenorphine use. Buprenorphine does not cause a high euphoric response and blocks the effects of other opioids which might. Thus the stimulation of the reward system is stopped, allowing the patient to undo some of the damage via a deliberate reconditioning process. Meanwhile a slow taper of the buprenorphine slowly resolves the physical dependence.

It's buprenorphine's suppression of cravings which makes the necessary behavioral changes possible. Although some of the tolerance and physical dependence is maintained while in buprenorphine treatment, the craving-causing brain adaptations of addiction are allowed to diminish. Since buprenorphine treatment does not perpetuate the reward/craving cycle, the patient is free to make significant behavioral changes which would be more difficult if cravings and withdrawal were present.