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The Addiction Puzzle, Part 2: Could ADHD Meds Promote Future Cocaine Use?

CAS prof says correct diagnosis and medication key to avoiding drug habit

“Ritalin is not very different from cocaine, and it’s the most popular ADHD medication. There’s a lot of controversy still surrounding the use of that drug, whether it renders individuals more vulnerable to abusing drugs later on or less vulnerable.”

Know any adolescents who take Ritalin? Chances are high that many people do, given that an estimated 6.4 million children between 4 and 17 in the United States have been diagnosed with attention deficit hyperactivity disorder.

In the United States, more than 60 percent of people diagnosed with attention deficit hyperactivity disorder (ADHD) take a stimulant medication, such as Ritalin, to control their symptoms, while about 20 percent use a nonstimulant, like Strattera. Both drugs help people focus and adjust to a changing environment, and to succeed in school or work. That’s a source of comfort for those living with ADHD and their families.

But what may be discomforting is the clinical research suggesting that one in five people diagnosed with ADHD as adolescents develop cocaine habits as adults. Most researchers don’t think ADHD medications are the culprit, but Kathleen Kantak has a different idea, and it’s based on at least five years of research made possible through funding of $2.25 million from the National Institute on Drug Abuse. The College of Arts & Sciences professor of psychology has examined the link between ADHD and cocaine use through a series of experiments in her animal laboratory, and her work suggests that the type of ADHD medication prescribed and the accuracy of a doctor’s diagnosis may contribute to future cocaine use.

“Ritalin is not very different from cocaine, and it’s the most popular ADHD medication,” Kantak says. “There’s a lot of controversy still surrounding the use of that drug, whether it renders individuals more vulnerable to abusing drugs later on or less vulnerable.”

Kantak’s target population has been adolescents. Clinical studies published in Pediatrics and the American Journal of Psychiatry show that teenagers diagnosed with ADHD who start taking Ritalin, but stop before reaching adulthood, could be twice as likely to develop a cocaine habit later on, this at a time when the number of those 4- to 17-year-olds has increased 16 percent since 2007 and jumped 41 percent over the past decade, according to the Centers for Disease Control and Prevention. Kantak says there is no evidence that younger children and adults who take Ritalin are at increased risk, and the link suggested by her research affects only adolescents. She says she finds it particularly alarming that nearly one in five high school–age boys has been given the diagnosis, a figure that is, curiously, twice that of girls in the same age group.


Source of data: the Centers for Disease Control and Prevention. View full size

“Adolescence is the period of the most rapid development of brain structure and function, particularly in the prefrontal cortex, which is the site of dysfunction in ADHD,” she says. During the teenage years, the brain’s wiring is going through a natural spurt of proliferation and pruning. “You can give drugs…during adulthood or during the juvenile stage and it may not have much of a long-lasting impact,” she explains. “But you take a brain that is very rapidly transitioning, you add a pharmacological agent on top of that, and you increase the risk of having some long-term consequences.”

Kantak’s experiments used three types of rats to test her hypothesis that certain ADHD medications taken during adolescence may contribute to future cocaine use. The first type, the spontaneously hypertensive rat (SHR), shows some of the same behavioral characteristics as people with ADHD, such as memory and learning deficiencies as well as an inability to easily shift from one task to another—a process known as set-shifting. Kantak compared the behavior of this type to that of two controls, the inbred Wistar-Kyoto (WKY) and the outbred Wistar—both of which are commonly used in animal experiments and do not display ADHD-like characteristics. In addition to observing their behavior, she tested whether these types of rats reacted differently to drug therapies targeting ADHD.

Graduate students and other assistants working in Kantak’s lab took each rat group through paces designed to measure their set-shifting ability. They then gave the rats Ritalin, Strattera, or no drug, and measured set-shifting again to see if the drug was working to counter ADHD symptoms in the SHR rats. All rats were taken off medications at the end of their adolescence.

Kathleen Kantak, ADHD prescription medication, cocaine addiction

Chloe Jordan (GRS’15) (from left), Britahny Baskin (CAS’13), and Kantak review results from recent research conducted in Kantak’s laboratory. Photo by Cydney Scott

Kantak’s team then tested their adult rats’ vulnerability to cocaine use. Each animal was implanted with a catheter and placed in a chamber equipped with a lever that when pressed, allowed them to take cocaine at will. The researchers first looked at how quickly the animals acquired a coke habit, defined as taking at least 20 infusions within a two-hour period for two consecutive days. They found that the SHR rats—whether or not they received Ritalin as adolescents—acquired a habit faster than the WKY or Wistar types. They also learned that SHR rats that received Ritalin as adolescents found cocaine more rewarding as adults than SHR rats that hadn’t received Ritalin as adolescents. The SHR Ritalin rats eagerly pursued their next hit, and they reacted to cues associated with cocaine delivery more than the other strains. Neither the inbred nor the outbred control rats, even those that had received Ritalin as adolescents, picked up a habit.

The researchers concluded that Ritalin pushes only those rats with ADHD-like characteristics toward greater cocaine use, and it does so only if the Ritalin was taken during adolescence.

When the SHR rats received the nonstimulant Strattera as adolescents, they were not quicker to acquire a cocaine habit. The same was true in the Wistar rats. But Strattera had the opposite effect on WKY rats, which do not exhibit ADHD-like characteristics. As adults, these rats were quicker to acquire an addiction to cocaine than those that never took the drug.

The results of Kantak’s research could present a dual cautionary tale for adolescents diagnosed with ADHD. “If they’re an adolescent getting a stimulant medication, and they’re properly diagnosed, the medication may put them at increased risk” for cocaine use as an adult, Kantak says. “If they’re misdiagnosed, and get Strattera, this may also be putting them at greater risk…of acquiring an addiction to cocaine.”

Kantak’s bottom line? She thinks adolescents properly diagnosed with ADHD should take either Strattera or another nonstimulant medication, while those whose diagnosis is doubtful would be wise to stay away from Strattera. She also believes pediatricians need to be especially careful when arriving at diagnoses. At the same time, she cautions parents who may see certain symptoms and “convince themselves that their child has ADHD, while what they really want is to give them a better competitive edge.” That edge could have dire circumstances down the line.

Kantak is currently examining what effect continued use of ADHD medication, through adolescence and into adulthood, has on acquiring a cocaine habit. She is comparing Ritalin with amphetamine—another stimulant used frequently to treat ADHD in the United States and Europe—to test each drug’s effectiveness in treating symptoms and tendency to promote future cocaine use. And she also hopes to study nicotine’s interaction with ADHD medications, because, she says, “up to half of teens with ADHD smoke.” She thinks this may put them at higher risk for abusing other substances down the line.

The Addiction Puzzle

Tomorrow, in part three of our series, a CAS researcher explores how unconscious triggers influence self-control when people are given the opportunity to drink alcohol.

Leslie Friday, BU Today, Boston University
Leslie Friday

Follow Leslie Friday on Twitter at @lesliefriday.

22 Comments on The Addiction Puzzle, Part 2: Could ADHD Meds Promote Future Cocaine Use?

  • Emily on 11.19.2013 at 2:26 am

    Her experiment was on rats, not humans. I am not a rat. As to whether or not stimulants increase the risk of cocaine use, This researcher has added nothing to our knowledge. First, if a person has adhd they are more likely to use drugs, period. Second, drug use among those with adhd may be a form of self-medication. Thrird, well treated adhd, whether with stimulants or Strattera reduces the risk of drug abuse. What her study did show, is once treatment is started, don’t stop!

    • Kyle on 03.10.2014 at 7:36 pm

      You sound like someone whom has not taken much pharmacology or neuroscience to understand the brains function and how it correlates across species. Rats have the higher level learning centers needed to study addiction and drug liability. Secondly, there is a correlation important here because of the stimulant aspect. People that take ADHD or ADD medications do not seek opiod drugs any more than anyone else. However, because ADHD medication stimulate the same pathway as cocaine, it leads to an increased dependence. So, rather than “once treatment is started” maybe we should STOP OVER-PERSCRIBING!

  • Jeff on 11.19.2013 at 9:28 am

    Emily, In the same breath in which you question the use of rats in science experimentation you go on to quote several rat studies when you state matter-of-factly that people with ADHD are more likely to use drugs. This debate is happening on a level in which it is rather apparent you are not in the conversation. It is rather obvious that a control group is used in determining the deviation from ADHD (in this case, probably Spontaneously Hypertensive Rats) levels of addiction. This point also effectively dismisses your second.

    As in all science, finding out what we do not know is the only way of getting to a solid baseline of scientific knowledge. The studies done by Kantak’s lab are not meant to tell you that you are a rat, rather, they give us insight to areas of the brain that may or may not play a role in addiction, a behavior that needs better understanding in our society.

  • Kelly Cavanagh on 11.19.2013 at 10:26 am

    I did not read the whole article. I didn’t have to. I’ve seen Dr Joanna Fowler of Brookhaven National Lab and National Medal of Science award recipient speak about this. Please read this to the end. Cocaine and stimulants do have similar effects in the nervous system but only when given intravenously. You have to inject it. When taken orally it has a completely different effect on the brain and is undoubtedly helpful in treating ADHD. That is why long acting stimulants are much preferred over short acting, there is less chance of abuse.
    As a side note, ritalin taken orally has been shown in recent studies to be helpful in treating cocaine addiction. Do a search and you’ll find this in respected medical journals.

    • Kyle on 03.10.2014 at 7:39 pm

      It is not that it has a different effect on the brain. The matter is there is a therapeutic window on which these drugs are ideal for. Cocaine easily surpasses this window and gets you high. Amphet. salts (Ritalin) when taken per-orally work on the same parts of the brain, but within the therapeutic window, so there in are the benefits. Snort coke or Ritalin and you will get the same effects. The reason amphet salts seem to be a treatment for cocaine is when they are taken per-orally they trigger the same pathway of reward, but to a lesser extent, and for a much longer period of time.

  • squirrel on 11.19.2013 at 11:02 am

    It would be helpful if this article included information about the sample sizes involved in the study. This is critical information one needs in order to evaluate the validity of the findings. Emily is right, studying rats and studying people are very different, but animal studies are a first step towards understanding very complex public health issue in humans. More research is needed before conclusions about ADHD and drug use can be drawn.

  • BU Today on 11.19.2013 at 2:13 pm

    There are links in the article to PubMed where two of the published papers can be found (one on Ritalin and one on Strattera). The one on Ritalin (methylphenidate) is free to download from the PubMed site (either from the publisher or from PubMed Central) and the one on Strattera is free to download from the publisher if the reader is connected via the BU network. This will answer the question of group sizes as well as providing more context for the studies.

  • Emily on 11.19.2013 at 10:06 pm

    @ Jeff, I never mentioned any studies. But, the research I was referring to was done with humans, not animal models. Yes, animals can teach us many things, but they have limits which I was trying to point out. My comments were directed more at the article about the study, than the study. I have ADHD and was never treated with stimulants as a child or adolescent, yet I found myself “addicted” to Methamphetamine in my 30’s.since getting clean, I am a mess with my adhd symptoms. They really cause me daily distress! However, every psychiatrist I have been to refuses to prescribe me with the stimulants that would improve my quality of life. Why? Because of of articles like this, that over-simplify a complex issue and put fear into the minds of Doctors about treating people with adhd and sud with stimulants. Childhood adhd is horrible, but adult adhd is worse! Without stimulants, I can’t remember to pay bill, make necessary phone calls, organize paperwork, watch a movie with my girlfriend, or practice stress reducing activities. My mom and girlfriend manage my money, so I have a steady place to live. But the rest is always falling through the cracks. I know the benefits of stimulants for me and to get the because of some unrealized fear of a Dr just sucks!

    • Gina Pera on 03.11.2014 at 8:48 pm

      Yes, Emily. Unfortunately, methamphetamine is a real trap for people with untreated ADHD.

      I hope you can find a more enlightened MD who will work with you on suitable interventions. Keep trying….. There is an association of psychiatrists who treat people with SUD. Sorry I can’t remember the name right now. But that might be a place to start.


    • Tomd on 01.08.2015 at 4:47 pm

      Hi Emily.

      There is a huge difference between doctors and other professionals who study addiction and mental disorder ………and those of us who have longstnading personal experience with them both.

      I was not diagnosed with ADHD when I was a kid because I was born in 1966 and so they didnt know it existed unless the kid was literally freaking out and smashing things. I hid my symptoms by redoubling my efforts to be good at school, athletic and popular.

      As i got into adolescence I could no longer hold it all together with sheer will. I ended up falling into many of the maladies that are described with disastrous consequences for my myself, my friends and family.

      At age 15 I gravitated to smoking cigarettes and drinking coffee. Soon I was choking back a pack a day and 5 cups of coffee. We would skip out of school and ‘go for coffee’ every day. At some point, we would finish our coffee and my suggestion was to go for coffee. My friends would remind me that we just went for coffee. I wanted to go again.

      By 24 I became addicted to cocaine the 3rd time I tried it. I now had to deal with a 12 year cocaine career and when I had the gall to get off it for a while my ADHD would come back .

      Now I have found out that I had ADHD since I was 12 years old and it all could have been friggin avoided if I was born 20 years later.

      So dont worry. I understand where you are coming from. Just like addiction doctors who study the crap in books, they do not know what they are talking about because they have not lived it.

      Show us doctors who have the ADHD and I am pretty sure we will listen to them then.

  • steve on 11.20.2013 at 11:37 am

    The statement that stimulants help people succeed at work is not supported by scientific evidence. The only large study on the matter showed that those diagnosed with ADHD had employer approval ratings just as high as their non-ADHD counterparts, regardless of stimulant prescriptions. As to academics, it appears that stimulants help in the short term, but have no long-term benefits in any important outcome area for stimulant vs. non-stimulant users, including academic achievement, test scores, dropout rates, college enrollment, social skills, delinquency measures, or self-esteem. The only benefit to stimulant users was a decreased likelihood of serious accidents such as a motor vehicle crash.

    It is important not to overstate the long-term benefits, or lack thereof, especially when we consider the adverse effects that we might be inducing. Nadine Lambert got similar results on rats and cocaine use in her research years ago, and also found that smoking (another stimulant) is more common on adults treated with stimulants as a kid. It’s not something to ignore or dismiss.

    —- Steve

  • Cheryl on 11.20.2013 at 2:44 pm

    As a parent with an 11 year old on Ritalin for ADHD, this study should be taken into consideration. Any addiction at all is a concern, and I am now aware of the need to prevent it, following this article. Further research is obviously necessary as well as talking to the doctor prescribing Ritalin.

  • PsychProfessor on 11.23.2013 at 7:52 am

    This article claims that “1 in 5 people diagnosed with ADHD as adolescents develop cocaine habits as adults.” By my read, there is no support for this claim whatsoever.

    The journalist, Ms. Friday, provides a link to a case study/literature review in the American Journal of Psychiatry (AJP). First, citing this AJP article as evidence for this claim is not appropriate, as the AJP article is, itself, a secondary source (an article citing another article or study).

    Second, Ms. Friday misrepresents what’s stated in the AJP article, anyway. I read the AJP article carefully, and I don’t see any kind of assertion that ‘1 in 5 individuals diagnosed with ADHD as adolescents develop cocaine habits as adults’ ANYWHERE in the AJP article. Perhaps the journalist misread the AJP article? If 20% of cocaine users have ADHD, it does NOT logically follow that 20% of those with ADHD will develop “cocaine habits.”

    This BU Today article really should be corrected so that the public is not (further) misinformed.

  • Leslie on 11.25.2013 at 11:01 am


    Thank you for your comment. I corrected the link you’re referencing. The appropriate one should now be working. Please take a look.

  • William Maher on 12.03.2013 at 1:48 pm

    According to Dr. Peter Breggin(breggin.com), psychiatrist and former Harvard University Teaching Fellow, the dishonesty of Academia and the pharmaceutical industry reached new heights with the ADHD diagnosis. Most importantly, there is NO scientific biological marker to determine this recently contrived “disease.”

    Of course, the parental victims are never informed of this profound factor. A child could be diagnosed with ADHD by one doctor but then not so by a second and third doctor for the simple reason that there is no scientific basis to this potentially life-changing diagnosis. If a student is observed shaking his leg three times within a 10-second period, he must have ADHD? Give him a Schedule II drug, i.e., the amphetamine Ritalin! Hmmm…sounds scientific to me!I’ve noticed that ADHD experts never dare to enlighten their audiences as to the ADHD quotient in other countries such as Japan (Hint: there aren’t any Japanese pharmaceutical companies pulling in millions for psychotropic drugs to children). In Dr. Breggin’s book, “Talking Back to Ritalin,” he exhibits a notice from the U.S. DEA comparing the near identical properties found between methylphenidate(Ritalin) and cocaine. If you find a parent with a Ritalin-using child, ask the parent if the doctor reminded the parents that Ritalin is a Schedule II drug as designated by the FDA, i.e.: High Potential for Abuse; May lead to severe psychological or physical dependence(Don’t hold your breath waiting to find a parent who has been informed of this factor) One of the more salient points that Dr. Breggin makes is that no one knows what impact Ritalin has on a growing child’s brain, especially since the medical community knows almost nothing about the brain. He further adds that pro-ADHD doctors and the related pharmaceutical companies concede that physical growth is impeded by these stimulant drugs…and doesn’t that also mean that the size of the child’s brain is also impacted? I wish the pro-ADHD cohort would some day consider debating the ADHD issue in the highest public forum available against their premier adversaries such as Dr. Breggin. But again, don’t look to the pro-ADHD lobby for initiative in the area of an honest debate. The ADHD controversy has been around for decades now but I haven’t heard of a single major debate. I don’t think the ADHD lobby can afford a debate; they are wise. Of course, Dr. Breggin is not expecting his phone to ring any time soon.

    • Jessica R Byers on 08.22.2017 at 8:04 am

      The most intelligent ADHD related comment I’ve read online!! Finally, someone more intelligent than I put into words what I’ve always thought! Thank you for the comment, I have never heard of Dr. Bregging but I will research him now!

  • samantha on 12.15.2013 at 1:25 pm

    I usually never post, but after reading this article and the comments, I felt compelled to share my personal experience on the matter. I would first like to agree with Emily completely on many points she raised in her post, and commend her for her bravery by debating the article’s content, it takes courage to go against the conformity tide. I would like to add that I have ADHD along with a laundry list of other diagnoses, so I can offer my insight regarding stimulants since I’ve been taking Adderall with success for quite some time now. The medication has drastically alleviated my symptoms whereas without it, I would be in bed all day, not go to my classes, hand in all my assignments late if at all, and procrastinate any and everything I could–why do something today when you can put it off until tomorrow? But anything good always comes with a price…When I go to the pharmacy, it can be a nightmare and often is humiliating especially if there is a new pharmacy tech working that wants to play like a detective about to crack a case. I will be strangely looked at, asked ridiculous questions, and it pretty much makes me feel like a drug-seeking junkie almost every time without fail. Personally, I don’t like to tell people I’m even on Adderall because of all the negative connotations associated with this drug, and it makes me feel like I’m doing something wrong for some reason. Now this doctor has claimed that people taking stimulants are more likely to use cocaine? Well, please include me in your statistics as an officially diagnosed patient with ADHD for the last 15 years, and I am NOT a habitual or recreational cocaine user nor have any issues with substance abuse. I understand that some people abuse the drug, but I also don’t believe that the actions of some shouldn’t reflect all.

  • Gina Pera on 03.11.2014 at 8:41 pm

    I’m glad that Kantak is conducting this research. What I find problematic is that this information is presented to the public as if it’s undisputed fact instead of discussion points in the discovery process. And very narrow discussion points, especially given that we are talking about rat studies, not humans.

    Yes, rat studies are helpful, but they are no substitute for humans and longitudinal data.

    I find especially concerning quotes such as this from Kantak:

    “Ritalin is not very different from cocaine, and it’s the most popular ADHD medication,” Kantak says.

    Why would a researcher who has the best interests of the ADHD population at heart make such a ridiculous statement? Especially in an article targeting the public? Perhaps it is her own vainglory (and the university press office’s) that lead to the “puffiness” of this piece. Sorry to say, some scientists are more interested in their own PR than in careful parsing of the facts.

    At any rate, this is a complicated issue and is not best served by the unproven conclusions drawn in this piece. This subject matter requires careful reporting, with plenty of caveats. Real people’s lives depend on accurate understanding and portrayal of ADHD medications in the media. To thoughtlessly publish pieces that increase stigma and confusion only serve to bully these people. And they’ve had enough of that.

    A researcher much more highly cited than Kantak in the literature, Timothy Wilens, has published several papers on this topic, including this meta-analysis:


    Results: Six studies—2 with follow-up in adolescence and 4 in young adulthood—were included and comprised 674 medicated subjects and 360 unmedicated subjects who were followed at least 4 years. The pooled estimate of the odds ratio indicated a 1.9-fold reduction in risk for SUD in youths who were treated with stimulants compared with youths who did not receive pharmacotherapy for ADHD (z = 2.1; 95% confidence interval for odds ratio [OR]: 1.1–3.6). We found similar reductions in risk for later drug and alcohol use disorders (z = 1.1). Studies that reported follow-up into adolescence showed a greater protective effect on the development of SUD (OR: 5.8) than studies that followed subjects into adulthood (OR: 1.4). Additional analyses showed that the results could not be accounted for by any single study or by publication bias.

    Conclusion: Our results suggest that stimulant therapy in childhood is associated with a reduction in the risk for subsequent drug and alcohol use disorders.

  • Gina Pera on 03.11.2014 at 8:46 pm

    As for this:

    “Kantak’s bottom line? She thinks adolescents properly diagnosed with ADHD should take either Strattera or another nonstimulant medication, while those whose diagnosis is doubtful would be wise to stay away from Strattera.”

    No reader should come away from this page with the idea that this has been proven or is in any way peer-reviewed and validated.

    Plenty of studies examine the efficacy of stimulants vs. atomoxetine, and stimulants largely show greater efficacy. Moreover, there is actually a higher side effect profile with atomoxetine.

    Please keep in mind: There are known and proven risks to untreated ADHD as well.

  • Anon on 03.21.2014 at 11:06 am

    “Conclusion: Our results suggest that stimulant therapy in childhood is associated with a reduction in the risk for subsequent drug and alcohol use disorders.”

    As you correctly quoted, stimulant treatment in childhood does not appear to increase the risk for substance use disorder later in life.

    However, Dr. Kantak’s research is clearly focused on ADHD treatment in adolescents, not children. The adolescent brain is very different from a younger child’s brain from a developmental perspective. It makes sense that stimulant treatment during adolescence probably has different effects and long-term consequences than during childhood.

    Although it is obvious that much more sound research needs to be conducted in humans (like not lumping children and teenagers together in a meta-analysis) before we start cautioning against prescribing Ritalin to adolescents, I think that Dr. Kantak’s message should be taken seriously. Why would we even want to take the slightest chance at putting our teens at higher risk for abusing drugs???

  • BL on 07.31.2014 at 6:48 am

    My teen son had taken Adderal and recently Ritalin. If anything he is very consious about not abusing any type of drugs. When in pain with a headache, he often decides not to take Tylenol. After surgery recently, he was in terrible pain, but refused to take prescription pain killers because he heard that they were addictive.

    That said, he takes the Ritalin, because without it, his life was living hell. He could not control impulses that got him in trouble at school and at home. He could not sit and do his homework or study for a test. He could not interact positively without this medication. It wears off each day, sonwe daily get a reminder of life without Ritalin, he must finish his homework before it wears off.

    I pose a theory, but I would say that those who suffer similar symptoms and go untreated, will end up with poor grades, later poor career prospects, a poor standard of living, unsatisfactory personal relationships amd more. So if looking for future effect of taking Ritalin, why not study effect of NOT taking it, for those with these crippling symptoms. Could lead to many negative outcomes, Drug/alcohol use being one of them. Can go either way. All drug use must involve weighing the benefits and costs. People are focusing on the costs and ignorig the benefits.

  • CC on 12.04.2014 at 2:45 pm

    Someone should do an official study on people checking into to drug and alcohol treatment centers. I work at one and noticed that a majority of the young people admitting were given ADHD drugs as children.

    Having been prescribed ADHD drugs myself I think they produce better high than cocaine, it lasts longer, but like cocaine the comedown hurts and its self medicating the comedown/crash that leads to the alcohol and abusing of other substances. That’s how it went for me.

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