'Nurse Jackie' returned for a final season on Showtime on Sunday night and once again received praise for its realistic portrayal of addiction. At the start of last season, I asked an expert about the chances that I'd ever receive care from an addicted medical professional and if I did, would she still be able to handle the job.

The answer, from Lisa J. Merlo, an assistant professor of psychiatry at the University of Florida who has studied the prevalence and impact of drug abuse among medical professionals, was basically: It's not likely. And if it happens, that nurse's or doctor's skills probably will still be intact.

Research, including Merlo's, shows that docs and nurses are a lot like the rest of the population when it comes to drug addiction -- they become addicted at similar rates. Of course, they have much better access to the drugs they want; one study shows that they obtain them by "stealing from the office or hospital, by defrauding patients and insurers, by using medication samples and by misusing valid prescriptions." (The prescription drug abuse epidemic among patients has narrowed the access gap.)

Still there are plenty of horror stories. In this one from Men's Health, a drug-addicted surgical tech exposed nearly 6,000 patients to hepatitis C.

Medical professionals also tend to get much better care when they seek it, or are required to get it, so they have much higher rates of recovery than the general population. In this study by a team that included Merlo, 78 percent of the 904 doctors who went through a rehab program were drug- and alcohol-free during the five years of intensive monitoring that followed, and 72 percent were continuing to practice medicine.

Here are some excerpts from that Q & A from May 27:

How prevalent is abuse of prescription drugs by physicians? Should I be concerned that my health-care provider’s judgment or skill are impaired by overuse of these drugs?

Previous research by other scientists has estimated that lifetime rates of substance use disorders range from 10 to 15 percent among physicians. This does not mean that 10 to 15 percent  of physicians are impaired at any one time. Some recover through treatment or on their own; others leave medicine. Plus, not all physicians who abuse substances do so while they are at work. The number of physicians who are impaired by substance use on the job is likely quite low.

Can health care providers function well at work but truly be dependent on, or addicted to, drugs?

In most cases, work performance is the last thing to go. Many health-care professionals with addiction function very well at work, often avoiding substance use while on the job, even if they are using significant amounts in their “off time.” Once work performance is impaired, it is likely that the addiction is quite severe.

Some addicted health-care professionals admit to using substances to stave off withdrawal during the workday. The level of impairment they experience would depend on the substance being used, the dose they are using, their level of tolerance and the complexity of the work they are performing.

Is there anything distinctive about physicians who abuse drugs as opposed to drug addicts in the general population?

The primary difference between physicians with addiction and individuals from the general population with addiction is the quantity and quality of treatment they receive. Physicians are typically mandated to 90 days of residential treatment, followed by five years of monitoring with random drug tests. As a result, rates of recovery exceed 80 percent, even five years after treatment.

By contrast, individuals in the general population are frequently unable to obtain residential treatment until they “fail” lower levels of care by relapsing. Even if they participate in treatment, they typically have no follow-up monitoring. As a result, rates of recovery in the general population are closer to 20-50 percent at one year after treatment.