The polarized legalization debate leads to exaggerated claims and denials about pot’s potential harms. The truth lies in between.<\/b><\/p>\n
Pretty much everyone who has spent time smoking marijuana knows at least one diehard stoner. The guy whose eyes are always red, the girl who doesn\u2019t use the term \u201cwake and bake\u201d ironically, the person who just can\u2019t seem to ever get it together. These heavy smokers might work at a low-level job or they may be unemployed\u2014but everyone who knows them well knows that they are capable of much more, if only they had any ambition.<\/span><\/p>\n Is this really addiction? I believe that it is (and I don\u2019t think that\u2019s an argument against legalization). In fact, the reasons why marijuana is addictive elucidate the true nature of addiction itself.\u00a0 Addiction is\u00a0<\/span>a relationship<\/span><\/i>\u00a0between a person and a substance or activity; addictiveness is\u00a0<\/span>not<\/span><\/i>\u00a0a simple matter of a drug \u201chijacking the brain.\u201d In fact, with all potentially addictive experiences, only a\u00a0<\/span>minority<\/a><\/span><\/span><\/span>\u00a0of those who try them get hooked\u2014and people can even become addicted to apparently \u201cnonaddictive\u201d things, like\u00a0<\/span>carrots<\/a><\/span><\/span><\/span>.\u00a0Addiction depends on learning, context and psychology, not just neurotransmitters.<\/span><\/p>\n With two states having already legalized recreational marijuana use and several more considering doing so, understanding the nature of addiction is more important than ever. Partisans on both sides of the debate have made extreme claims here; some legalizers saying there\u2019s no such thing as marijuana addiction, while some prohibitionists claim\u00a0<\/span>\u201ccannabis as addictive as heroin.\u201d<\/a><\/span><\/span><\/span><\/p>\n Our concepts of addiction, however, come primarily from cultural experience with alcohol, heroin and, later, cocaine. No one has ever argued that opioids like heroin don\u2019t have the potential to cause addiction because the withdrawal symptoms\u2014vomiting, shaking, pallor, sweating and diarrhea\u2014are objectively measurable. Opioids cause physical dependence that is evident when they become unavailable. The same is true for alcohol, where withdrawal is even more severe and can sometimes even be deadly.<\/span><\/p>\n So early researchers focused on these measurable symptoms related to alcoholism and opioid addictions in defining addiction: Using a drug could lead to becoming tolerant to it, tolerance could lead to dose escalation, which could in turn lead to physical dependence, and then the addiction could be driven by the need to avoid the painful symptoms of withdrawal. It was simple and physical.<\/span><\/p>\n In this view, however, cocaine and marijuana were not \u201creally\u201d addictive. While people can experience withdrawal symptoms like irritability, depression, craving and sleep problems when quitting these drugs, these are much more subjective and therefore can be dismissed as \u201cpsychological\u201d rather than physical. You might really\u00a0want<\/i>\u00a0coke or pot, but you didn\u2019t\u00a0need<\/i>\u00a0it like a\u00a0real<\/i>\u00a0junkie, the thinking went.<\/span><\/p>\n And since most of us like to believe that we have much more control over our minds than we do over physical symptoms, \u201cpsychological\u201d addiction is seen as far less serious than the \u201cphysical\u201d type. It\u2019s the remnants of this kind of thinking that mainly underlie the idea that marijuana addiction doesn\u2019t exist. Unfortunately, that view of addiction is stuck in the 1970s.<\/span><\/p>\n In the 1980s\u2014ironically, not long after\u00a0<\/span>Scientific American<\/span><\/i>\u00a0caused a big controversy by\u00a0<\/span>arguing<\/a><\/span><\/span><\/span>\u00a0that snorted cocaine is no more addictive than eating potato chips\u2014entrepreneurs began marketing a ready-made smokeable form of the drug. The birth of crack shattered the idea that \u201cphysical\u201d dependence is more serious than psychological dependence because people with cocaine addictions don\u2019t vomit or have diarrhea when they quit; while they may appear desperate, it\u2019s not in the physically obvious way of heroin or alcohol withdrawal. And so, if you are going to argue that marijuana is not addictive because you don\u2019t get sick when you quit, you also have to argue the same for crack.<\/span><\/p>\n In the 1970s view, cocaine and marijuana were not \u201creally\u201d addictive: You might really want coke or pot, but you didn\u2019t\u00a0<\/i>need<\/i>\u00a0it like a\u00a0<\/i>real<\/i>\u00a0junkie, the thinking went.<\/i><\/span><\/p>\n Good luck with that one, I say. Clearly, crack-addicted people are every bit as compulsive as those with heroin problems\u2014and their criminal involvement if they can\u2019t afford the drug is at least equally likely, though not as common as has been claimed. Crack dealt a deathblow to the \u201cpsychological\u201d vs. \u201cphysical\u201d distinction\u2014and if it hadn\u2019t, neuroscience was creeping up to show that the psychological and the physical aren\u2019t exactly distinct anyway.<\/span><\/p>\n In the \u201870s and \u201880s, researchers also began recognizing that simply detoxing heroin addicts\u2014getting them through the two-week period of intense physical withdrawal symptoms\u2014is not effective treatment. If heroin addiction was driven primarily by the need to avoid withdrawal, addicted people should be out of the woods after they complete cold turkey. But as those of us who have been through it know, that is far from the hardest part.<\/span><\/p>\n While kicking heroin isn\u2019t fun, staying off it in the long run is the problem\u2014those \u201cmere\u201d psychological cravings are what drive addiction. Physical dependence isn\u2019t the main problem; it isn\u2019t even necessary. Indeed, we now know that you can actually have physical dependence without any addiction at all: There are some blood pressure medications, for example, that can have deadly withdrawal symptoms if not tapered properly, but people on these meds don\u2019t crave them even though they are quite dependent. Similarly, antidepressants like Paxil have physical withdrawal symptoms, but because they don\u2019t produce a high, you don\u2019t see people robbing drug stores to get them.<\/span><\/p>\n So what is addiction, then, if tolerance, withdrawal and physical dependence aren\u2019t essential to it? All of these facts point to one definition that can sum up the problem: Addiction is compulsive use of a substance or engagement in a behavior despite negative consequences. (Put more in neuroscience, addiction is a learned distortion in the brain\u2019s motivational systems that make us persist in pursuing things linked to evolutionary fitness like food and sex.) Anything that causes pleasure via these systems\u2014and that\u2019s basically anything that is possible to enjoy\u2014can be addictive to some person at some time. And that includes marijuana (and, for that matter potato chips).<\/span><\/p>\n This doesn\u2019t mean that marijuana addiction is necessarily as severe as cocaine, heroin or alcohol addiction\u2014in fact, it typically isn\u2019t. If given the choice, most families would vociferously prefer having a member addicted to marijuana rather than to cocaine, heroin or alcohol. The negative consequences associated with marijuana addiction tend to be subtler: lost\u00a0promotions<\/i>, for example, rather than lostjobs<\/i>;\u00a0worse<\/i>\u00a0relationships, not\u00a0no<\/i>\u00a0relationships. And of course, no risk of overdose death.<\/span><\/p>\n Marijuana addiction may quietly make your life worse without ever getting bad enough to seem worth addressing; it may not destroy your life but it may make you miss opportunities.<\/i><\/span><\/p>\n But this is also what can make it insidious. Marijuana addiction may quietly make your life worse without ever getting bad enough to seem worth addressing; it may not destroy your life but it may make you miss opportunities. With any pattern of regular drug use, it\u2019s important to continually track whether the risks outweigh the benefits, keeping in mind that addiction itself may distort this calculation. This is especially true with marijuana.<\/span><\/p>\n However, as with all other drugs, only a minority of marijuana users ever struggle with addiction. Research suggests that about 10% get hooked\u2014and on average, marijuana addiction lasts six years. Even more than other addictions, marijuana addiction seems to be driven by self-medication of mental health problems\u2014<\/span>90%<\/a><\/span><\/span><\/span>\u00a0of people with marijuana addiction also have another addiction or mental illness, typically alcoholism or antisocial personality disorder.<\/span><\/p>\n This suggests that exposing more of the population to marijuana won\u2019t necessarily increase the addicted population. First, people with antisocial personality disorder, by definition, tend not to be law abiding, so most have probably already tried it. Second, the percent of people with other pre-existing mental illness will not change because marijuana becomes legal\u2014in fact, in the UK, when they reversed their prior liberalization of marijuana law because of fears related to increased schizophrenia, psychosis rates\u00a0<\/span>actually went up<\/a><\/span><\/span><\/span>. (The link probably wasn\u2019t causal, but it does suggest that legal crackdowns on cannabis don\u2019t prevent related psychosis).<\/span><\/p>\n If some people with alcohol, cocaine or heroin addiction switch to marijuana instead, overall harm would be reduced.\u00a0As I and others have been reporting at least since 2001, using marijuana as an \u201cexit\u201d drug is a real phenomenon, both in\u00a0<\/span>cocaine<\/a><\/span><\/span><\/span>\u00a0and\u00a0<\/span>opioid<\/a><\/span><\/span><\/span>\u00a0addiction.<\/span><\/p>\n When we consider the risks of various substances, we tend to do so in isolation\u2014but that\u2019s not how choices are made in the real world. Most people would rather their partners have no addictions\u2014but again, some are clearly worse than others. Marijuana craving is rarely as severe as crack craving, as is obvious.<\/span><\/p>\n Still, like anything that can be pleasurable, marijuana\u00a0can<\/i>\u00a0be addictive. This doesn\u2019t mean all addictions are the same or that it is as addictive as the currently legal drugs alcohol and tobacco\u2014the data shows it is less so. <\/span><\/p>\n Pretending it can\u2019t do any harm at all, however\u2014or that there aren\u2019t people who are addicted to it\u2014does no one any good.\u00a0If we want better drug policy, as with other types of recovery, we need to avoid denial.<\/span><\/p>\n Maia Szalavitz\u00a0<\/a><\/span><\/i><\/span><\/span>is one of the nation\u2019s leading neuroscience and addiction journalists, and a columnist at<\/span><\/i><\/span>\u00a0Substance.com<\/i><\/span>. She\u00a0has contributed to\u00a0<\/span><\/i><\/span>Time<\/i><\/span>,\u00a0<\/span><\/i><\/span>the New York Times<\/i><\/span>,\u00a0<\/span><\/i><\/span>Scientific American Mind<\/i><\/span>,\u00a0<\/span><\/i><\/span>the Washington Post<\/i><\/span>\u00a0and many other publications. She has also published five books, including\u00a0<\/span><\/i><\/span>Help at Any Cost: How the Troubled-Teen Industry Cons Parents and Hurts Kids<\/a><\/span><\/i><\/span><\/span>\u00a0<\/a><\/span><\/i><\/span><\/span>(Riverhead, 2006), and is currently finishing her sixth,\u00a0<\/span><\/i><\/span>Unbroken Brain,<\/i><\/span>\u00a0which examines why seeing addiction as a developmental or learning disorder can help us better understand, prevent and treat it.\u00a0Her last column for\u00a0<\/span><\/i><\/span>Substance.com\u00a0<\/i><\/span>was\u00a0about\u00a0<\/span><\/i><\/span>why the oft-documented fact that most people age, or grow, out of substance misuse is not common knowledge.<\/a><\/span><\/i><\/span><\/span><\/p>\n