Opioid use disorder is the official American Psychiatric Association term for all diagnosable cases of addiction to an opioid drug or medication, as well as all diagnosable cases of a non-addicted, destructive pattern of opioid drug or medication abuse. In any given year, some of the people who legitimately hold a prescription for an opioid medication will develop the symptoms of this disorder. In a study published in May 2014 in the journal Drug and Alcohol Dependence, researchers from four U.S. institutions sought to identify the primary factors that make an opioid prescription user susceptible to the onset of opioid use disorder. Substance Use Disorder The American Psychiatric Association classifies both substance addiction and disruptive substance abuse as mental health concerns. The umbrella term used to define these problems is substance use disorder. Since people affected by physical dependence and addiction often have symptoms also found in people participating in a non-addicted pattern of substance abuse (and vice versa), the substance use disorder diagnosis does not treat addiction and abuse as separate issues. Instead, doctors can identify a minimum of two and a maximum of 11 symptoms that indicate the presence of addiction and\/or abuse. Opioid use disorder is the subtype of substance use disorder reserved for diagnosing cases of abuse\/addiction involving either an opioid narcotic drug like heroin or an opioid narcotic medication such as hydrocodone, oxycodone, fentanyl or codeine. Extent of the Problem Each year, the federal Substance Abuse and Mental Health Services Administration uses information from a project called the National Survey on Drug Use and Health (NSDUH) to roughly determine how many American adults and teenagers use a prescription opioid medication for unintended or nonmedical purposes. This information is critically important, since people who don\u2019t strictly follow a doctor\u2019s dosing instructions for these medications sharply increase their chances of eventually qualifying for an opioid use disorder diagnosis. According to figures gathered from the last available version of the NSDUH (completed in 2012), opioid pain relievers are by far the most commonly misused prescription medications across the U.S. Approximately 1.9 percent of American adults and teens misuse these medications in the average month; this rate of inappropriate intake outpaces the combined rate for the three other most commonly misused classes of medication: tranquilizers, stimulants and sedatives. Who Is At-Risk? In the study published in Drug and Alcohol Dependence, researchers from the University of Montana, the University of Colorado, Milliman Inc. and UC San Francisco used information obtained from an insurance industry database to identify the factors that increase any given prescription opioid user\u2019s chances of developing a diagnosable case of opioid use disorder. This information included things such as the basic demographic backgrounds of prescription opioid users (age, race\/ethnicity, gender, etc.), users\u2019 records of physical and mental health and users\u2019 history of accessing healthcare resources. The researchers also used data gathered from the insurance industry to identify prescription opioid users who were diagnosed with opioid use disorder two years or less after they first started taking an opioid medication. After reviewing the data, the researchers identified eight factors that make it more likely that a prescription opioid user will receive an opioid use disorder diagnosis within a two-year time span. These factors are being male, being relatively young, having a history of using more than one prescription opioid, maintaining a large supply of opioid medications, filling opioid prescriptions at multiple pharmacy locations, having a history of mental illness, having a history of accessing mental or physical healthcare and having a history simultaneously using other non-opioid medications. It\u2019s vital to note that all of the risk factors identified in the study published in Drug and Alcohol Dependence appear in prescription opioid users who don\u2019t develop opioid use disorder, as well as in prescription users who do develop the disorder. However, these factors appear substantially more often in prescription users who develop opioid use disorder. When the researchers used the listed factors to predict which individuals will receive a diagnosis for the disorder, they concluded that the combination of these factors acts as an accurate indicator 79.5 percent of the time. Based on this finding, they believe that their work can help addiction specialists and public health officials identify prescription opioid users with the highest risks for opioid use disorder, and also help improve the quality of prevention efforts designed to deter the onset of diagnosable problems.