I’m going to pose a question—Can a person get addicted to marijuana?—and then I’m going to duck, because people are going to start hurling sharp objects (or at least sharp words) at me.

Some people will no doubt declare, Of course people get addicted to it. Just look at all the “potheads” who smoke it day after day. Others will certainly scoff, No way is pot addictive! Look at all the people who only tried it a few times or only smoke it once in a while!

So before we jump into the fray, let me say up front that I have no moral agenda here. I’m not anti-pot or pro-pot. I’m a health journalist, and I just want to get at the truth.

Why now? Because marijuana is increasingly accessible and acceptable. Last year, Colorado and Washington became the first states to legalize recreational use of marijuana, and now four more (California, Arizona, Oregon, Alaska) are preparing referendums for legalization in 2014. Also, the drug has legitimate medicinal value, particularly for the relief of pain and nausea (click here for more on that topic), and already 20 states plus Washington, DC, allow marijuana for medical use.

But when we set aside the issues of legal status and medicinal benefit, we’re still left with the question of whether or not it is possible for people to become addicted to this particular drug. So I took that query to a top expert on drugs and addiction, J. Wesley Boyd, MD, PhD, assistant clinical professor of psychiatry at Harvard Medical School and author of Almost Addicted: Is My (Or My Loved One’s) Drug Use a Problem? His answer, in short, was, “Yes, marijuana definitely can be addictive for some people.”

Before we get into the reasons for his answer, let’s address one obvious concern. If pot is addictive, why do plenty of generally intelligent people claim otherwise? One reason is that regular marijuana use is less damaging than regular use of many other drugs, so by comparison it doesn’t seem like a big deal…but that doesn’t make it benign. Another reason is that denial is a hallmark of regular drug use, meaning that those who are caught up in using a substance often deny that their use is a problem…because they don’t want to stop using. In other words, by denying that anyone has a problem with pot, they can more easily ignore what may be their problem with it.

Based on my previous research into this subject and on my recent discussion with Dr. Boyd, I would ask any doubtful reader to at least consider the idea that marijuana can be addictive for certain people, the same way that alcohol is addictive for certain people and not for others. Then think about these reasons that pot should be recognized as a potentially addictive drug…

Pot use can damage lives. One defining aspect of addiction is that chronic use of the substance leads people to repeatedly engage in unhealthy and destructive behaviors despite the negative effects that those behaviors have on various areas of their lives.

For addicts, the negative consequences of their substance use often seem like an acceptable price to pay—because that is the only way they can justify their continued use. Dr. Boyd said, “If people are using marijuana all day, every day—and I’ve seen quite a number of such people in my practice—and if it is causing serious harm in their lives and yet they do not stop, then it’s an addiction.”

Of course, not all pot smokers fall into this category. Just as there are people who are able to drink alcohol in moderation, there are marijuana smokers who can use the drug occasionally or even with some regularity without becoming addicted. “Some people can smoke a joint in the evening and feel relaxed. I’d put that on par with having a drink or two in the evening after work,” Dr. Boyd said.

But: When people find they cannot make it through the day without smoking pot or have to smoke every evening, there’s a problem…just as there is a problem when people drink in the morning or have to drink every single evening. Likewise, when people risk their own or their family’s safety or well-being—by, say, driving under the influence of marijuana, showing up high at work or hiding pot in their suitcase when they travel to places where it is not legal because they cannot be without it—that’s a sign of addiction.

The damage done to a person’s life can increase over time as his dependence on pot grows. Example: In researching this article, I spoke with a man (I’ll call him “Greg”) who identifies himself as a recovering drug addict and who says that marijuana was, hands down, his top drug of choice. Greg told me, “I started out smoking just occasionally with friends. But after a while, I was smoking every day, then multiple times each day—in the morning, on breaks from work, late into the night. Eventually I stopped hanging out with friends who didn’t smoke, blew a whole lot of money buying pot, alienated my family and lost sight of my own values. At the time, believe it or not, I thought I was having fun—but looking back, I realize that pot took away everything that had been important to me. If that’s not addiction, I don’t know what is.”

Marijuana withdrawal syndrome does exist. We’re all familiar with the popular image of the detoxifying drug addict—profuse sweating, shaking hands, nausea, vomiting, sleeplessness and a host of other terrible symptoms. None of that happens when a marijuana user stops smoking (or ingesting) pot…but that doesn’t mean the user won’t experience other symptoms.

For instance, Dr. Boyd said, halting marijuana can cause a withdrawal syndrome similar to nicotine withdrawal (and few people would argue that nicotine is not addictive). Pot withdrawal symptoms can include irritability, difficulty sleeping, anxiety and increased aggression.

Even more problematic, though, is the intense craving for the drug, which can make giving it up very difficult. The phenomenon of craving is another hallmark of addiction, Dr. Boyd noted…and certain users do indeed crave marijuana when they try to or are forced to go without it.

Greg recalls having very strong cravings for pot. “Some of my smoking buddies could take it or leave it. But when I finally realized that I had a problem and tried to give up marijuana on my own, I never lasted more than two or three days. I just craved it too much, and I felt pissed off and depressed when I couldn’t have it.”

Pot can become a “substitute addiction.” The long-term physical effects of marijuana are not devastating like those of long-term alcohol abuse (cirrhosis of the liver, dementia, seizures, etc.)…and nobody dies of a pot overdose the way so many do from overdosing on cocaine, heroin, opioid painkillers or other drugs. In that sense, marijuana certainly offers a safer high.

That’s one reason why some people who recognize their addiction to alcohol or hard drugs switch to pot instead—in effect, trading their substance of choice for marijuana. This practice is sometimes jokingly called the “marijuana maintenance plan,” and according to Dr. Boyd, it is quite common. “People often try to control an addiction by substituting one addictive behavior for another—and substituting marijuana often is preferable to continuing to use more potentially devastating substances. But it’s not the same as being free from addiction, and it’s not an effective solution for the problems that active addiction causes,” he said.

It’s also important to recognize that chronic marijuana use is not benign in terms of its effects on health. Pot smoke contains 50% to 70% more carcinogenic hydrocarbons than cigarette smoke…it also increases the risk for chronic cough and bronchitis. Heart rate can escalate by 20% to 100% in the period shortly after smoking marijuana, an effect that can last up to three hours, dramatically raising some users’ risk for heart attack. According to a recent study, long-term use may reduce motivation levels by reducing production of the brain chemical dopamine. And in rare cases, chronic users may develop a side effect—ironically, since pot can be an effective treatment for nausea—called cannabinoid hyperemesis, characterized by repeated episodes of nausea, vomiting and colicky abdominal pain. Just as alcoholics may ignore the health risks of heavy drinking, pot addicts may dismiss the health risks of chronic marijuana use.

HOW COMMON IS POT ADDICTION?

According to the National Institute on Drug Abuse, an estimated 9% of people who use marijuana will become addicted to it. By comparison, 28% of American adults drink at levels that put them at risk for alcohol dependence…and more than 90% of smokers experience some of the symptoms of nicotine dependency with more than 60% becoming fully addicted.

In a recent review of 120 studies, researchers from the University of Montreal and the Icahn School of Medicine at Mount Sinai hospital in New York found that about one in four teenage users of marijuana develops an abusive or dependent (i.e., addictive) relationship with the drug. Genetics appears to play a role. For instance, the researchers noted that a predisposition to cannabis dependence can be inherited through the genes that produce the cannabinoid receptors situated in areas of the brain that govern learning, motivation, decision making, habit formation and more.

GETTING HELP

As I said, one insidious aspect of addiction is denial—addicts often have a very hard time recognizing that they are addicted. So if you use pot regularly, it’s important to be as honest with yourself as you possibly can in assessing your use. (For instance, when I told Greg about Dr. Boyd’s quote that “some people can smoke a joint,” he laughed and said, “The doctor means a skinny little joint, but potheads will tell themselves that this means it’s perfectly OK to smoke a big fat cigar-sized blunt every night. We pot addicts fool ourselves that way.”) So: If you have any suspicions that marijuana is a problem for you, confide in your doctor and discuss your options.

Generally, treatment for marijuana addiction is similar to that used for other addictive substances—it might include psychotherapy, participation in a 12-step program, and even outpatient or inpatient rehab. In fact, in 2009, approximately 18% of people ages 12 and older entering drug-abuse treatment programs reported marijuana as their primary drug of abuse, so you definitely don’t have to worry about being the only pot addict in a program. There are plenty of other people who share the same problem…and plenty of dedicated professionals who want to help you find a solution.

To find a psychologist who specializes in addiction issues: Check out the online locator of the American Psychological Association.

For 12-step programs modeled after Alcoholics Anonymous (AA): Contact Narcotics Anonymous (NA) or Marijuana Anonymous (MA). If you have trouble finding NA or MA meetings in your area, consider trying “open” AA meetings, which anyone can attend. (“Closed” AA meetings are limited to people with a desire to stop drinking. However, some marijuana addicts also identify themselves as alcoholics, in which case they generally are welcome at closed AA meetings.)

What happened to Greg? With the help of rehab, a 12-step program and a really great therapist, he got clean more than four years ago. Today he works as a substance-abuse counselor.