A minor increase in drug craving can cause a disproportionate hike in the likelihood that a person dealing with opioid addiction will pick up the drug, a new study has found.
Craving is one of 11 symptoms that doctors use to diagnose substance use disorder (substance abuse/substance addiction). In a study published in October 2014 in the journal Drug and Alcohol Dependence, a team of American researchers used clinical trials conducted at several locations to help determine how much the presence of opioid cravings increases the odds that a person affected by opioid addiction will consume more of an opioid drug or medication.
All opioid substances — including legitimately produced and consumed medications and illicitly/illegally produced and consumed drugs — significantly increase the brain’s levels of a pleasure-producing chemical called dopamine. A person who regularly consumes an opioid substance can grow accustomed to this dopamine increase and start experiencing urges for additional opioid consumption that take the form of conscious thoughts or unconscious feelings or sensations. These urges are opioid cravings. In many cases, such cravings appear as a direct or indirect result of exposure to drug cues, which are conscious or unconscious reminders of various aspects of the substance-using experience. An opioid user who has no other notable symptoms beyond drug cravings will not qualify for a diagnosis of substance use disorder (known in this situation as opioid use disorder). However, an opioid user who has at least one other symptom of problematic substance intake will qualify for an opioid use disorder diagnosis. Unfortunately, some longtime users develop opioid cravings even when they only consume prescription opioids in medically legitimate circumstances under the supervision of a doctor.
Opioid addiction is one of the two key aspects of opioid use disorder. Affected individuals have a physical dependence on the continued consumption of opioid drugs or medications. They also have additional symptoms of dysfunctional opioid use. Apart from opioid cravings, these symptoms can include loss of control over opioid intake, the repeated use of opioids in clearly dangerous and inappropriate circumstances, rising tolerance to the effects of opioid substances, the appearance of opioid withdrawal when opioid intake falls below a certain point and the continued use of opioids after exposure to serious personal, social or professional harm stemming from a current pattern of opioid intake. Some of the symptoms found in people with opioid addiction also appear in non-addicted people affected by diagnosable opioid abuse. For this reason, the opioid use disorder diagnosis covers opioid abuse as well as opioid addiction.
What’s the Impact of Craving?
In the study published in Drug and Alcohol Dependence, researchers from Harvard Medical School, Harvard-affiliated McLean Hospital, the Yale University School of Medicine and the University of Pittsburgh School of Medicine used trials conducted in multiple locations to help determine the extent to which a given level of opioid craving increases the odds that an addicted individual will consume more of an opioid drug or an opioid medication. The participants at each study location were receiving treatment for prescription opioid addiction. The researchers used brief questionnaires to place each participant’s level of opioid craving on a scale of 0 to 10. They compared the craving levels derived in this manner with the results of urine drug testing performed the following week.
The researchers concluded that craving levels recorded at any point in time affect the odds that a person dealing with opioid addiction will consume an opioid substance at some point during the next week. Specifically, they found that each single-point rise in craving levels on a 0-to-10 scale equates to a roughly 17 percent rise in the likelihood that additional opioid intake will occur. Factors that reinforce this likelihood include exposure to drug cues and a belief on the part of the affected individual that exposure to such cues will increase the chances of experiencing a relapse into uncontrolled opioid use.
The study’s authors concluded that their findings held true even after they accounted for each participants’ opioid intake in the last seven days, current severity of opioid use disorder and overall level of experience with heroin consumption. They believe that their work could significantly improve the efforts of addiction specialists seeking to identify those people most likely to relapse while taking part in treatment for prescription medication-related opioid use disorder.