I’ve recently completed a study that I presented at the Society For Neuroscience (SFN) meeting in DC. The study was actually aimed at looking at the usefulness of two medications in interfering with the rewarding qualities of methamphetamine. The thinking was the if we could figure out a way to interfere with crystal meth being perceived as rewarding by the brain, we may be able to help addicts from continued use after a relapse.
Two prescription stones but only one hits crystal meth
The two medications are atomoxetine and bupropion, though you may know them as Strattera and Wellbutrin or Zyban. Their mechanisms of action are similar, but distinct enough that we wanted to test them both. The results of the study, in one sentence, were that atomoxetine (or Strattera), but not bupropion (or Zyban) succeeded in eliminating animals’ preference for meth if given along with it. The implication is that in the future, these, or other, similar, medications, may be given to newly recovering addicts. The hope would be that by taking the drug, they may be somewhat protected in the case of a relapse. If they don’t enjoy the drug during the relapse, they may have a better chance of staying in treatment.
More to these medications than meets the eye
I learned some other interesting things while preparing, and then carrying out, the study. While Zyban could, by itself, be liked by the animals, Strattera did not seem to produce any sort of preference. Given the common use of these drugs in the treatment of ADHD, the difference may be very important. As you may recall, I’ve talked before about the connection between impulse control problems and being predisposed to developing addiction. Given this relationship, it would seem that we’d want to be especially careful about using drugs that can cause abuse with this population. Many of the stimulants used to treat ADD and ADHD can indeed lead to abuse, as their effects are very similar to speed, or crystal meth (Adderall and Ritalin come to mind). Zyban’s abuse liability is definitely lower, given the greatly reduced preference animals develop for it. Still, it seems that Strattera’s abuse potential is almost zero. In trial after trial, animals given atomoxetine fail to show a preference for the drug.
To my mind, this means that as long as it’s successful in treating the attention problems, atomoxetine is the better candidate. All in all, I’d think the first choice should be the one that helps the symptoms of ADHD while having a reduced likelihood of dependence. Obviously, if the drug is not able to treat the problem, other options should be selected, but it seems to me that given the known relationship between attention deficit problems and addiction, the question of abuse liability should play a significant role in the selection of medication.
Once again, this doesn’t mean that all users of Adderall, Ritalin, or the other stimulant ADHD medications will develop an addiction to their prescription. In fact, we know that rates of addiction to prescriptions are generally relatively low. Nevertheless, I’d consider ADHD patients a vulnerable population when it comes to substance abuse so I say better safe than sorry.