A recent study exposed that the drug modafinil (sold commercially as Provigil) is probably more addictive than anyone previously thought. Although the sample size was rather small (n=10 patients), the results indicated that modafinil, like ADD drug Ritalin and even nicotine, actually acts on the dopaminergic system, where the stimulation of "pleasure" neurotransmitters can lead to addictive tendencies.

Modafinil is used on-label to treat narcolepsy, and off label as a cognitive enhancement due to its ability to counter cognitive deficiencies caused by sleep deprivation. Considering the drug hit the market ten years ago, this late-revelation about the side effects of modafinil underscores the prevailing inadequate definition of addiction.

Let's look at the qualitative information available: 1) people feel good when they are on modafinil. 2) Things that reward us by making us feel good tend to be habit-forming. As more therapists begin to acknowledge the prevalence and consequences of other types of addictions, from sex addiction to video game addiction, the criterion of physical evidence to establish that a given chemical induces habit-forming properties loses its relevance. More and more, the leaders in the field of addiction research are moving away from a strictly reductionist theory of addiction.

The drug didn't even need to work as it was intended, or abused, for it to have been obvious that it posed a habit-forming risk. Reports have been around for several years exposing that some people seem to think that modafinil offers cognitive enhancing properties. As long as people form contracts with the chemicals they use and abuse--that is, as long as they routinely use the chemical for a specific purpose like studying, regardless of how effective it actually is--seemingly innate chemicals can become incredibly habit-forming to the individuals who habitually use them.

But more importantly, is there such a thing as an effective cognitive enhancement that is not habit-forming? To some, this statement might come of as implicitly troubling, since I choose to equate the treatment of a neurological condition with enhancement. I will not dwell on the philosophical aspects of why I see no problem equating the two, but I encourage you to refer to excerpts from my thesis or this excellent article from Nature . If it makes you feel more comfortable, we can change the sentence to read, "Is there such a thing as a treatment for fatigue that is not habit forming?" To explain why I see this sentence as irrelevant in a nutshell: there are no inherent moral guidelines regarding enhancement itself. That is to say, some things that are considered "enhancements," such as expensive tutors, are seen as acceptable, while others, like steroids in sports, are frowned upon. Therefore, it is not enhancement itself to which we take issue, but the specific instances of enhancement and the rules we establish within the niches where the enhancement is being used. By this line of reasoning, it is perfectly OK to call a cognitive treatment an enhancement as long as we accept that ALL medicine is a form of enhancement.

A simple answer to my question might appear to be that there could, eventually, be a cognitive enhancement that is not habit forming, if we pursue the development of drugs that treat symptoms and conditions without offering other cognitive benefits. Ideally, we'd eventually arrive at a drug that is like the aspirin of fatigue, used only "when necessary" to treat symptoms.

Herein lies the conflict: If you have chronic headaches and aspirin is your remedy, by any reasonable definition, aspirin is habit-forming. Feel yourself start to massage the temples? Grab an aspirin! Habits can emerge out of any rewards system presented to us. The absence of physical evidence that a substance is habit-forming in no way compromises the empirical imperative of biomedical research. Rather, empiricism needs to expand its scope to look for evidence in other places besides quantitative analysis. So I see no excuse for it to take ten years for researchers to finally confirm that a stimulating psychoactive drug that relieves the symptoms of fatigue, even in healthy people, is habit forming.

Of course, some habits are safer than other habits. Often, a recovering alcoholic will find that developing a healthier alternative habit, such as routine swimming, will help her refrain from falling off the wagon. Many of us suffer from addictive personalities, and so far the best we can do is form healthier addictions rather than avoid addiction all together.

I don't see much point evaluating the merits of a drug intended for daily use by measuring its habit-forming properties. If it were not habit-forming, does it make it safer to administer on a daily basis? Sure, to the extent that we all want control over the chemicals we put in our bodies. But doctors and drug makers need to begin admitting that all stimulating chemicals are clearly habit-forming at best and highly addictive at worst, depending on the way semantics affects your perception of drug safety. No one will die from the withdrawal symptoms of any stimulant, from Ritalin to modafinil to cocaine, and thus the degree to which they are irrevocably addictive has a great deal to do with the self-efficacy of the individuals trying avoid the chemicals. No drug is a miracle elixir devoid of side effects, and patients and doctors should assume that stimulants are habit-forming before deciding to begin a regimen. If, after careful meditation, the patient and doctor agree that the risks of addiction are outweighed by the cognitive benefits of the drug, it should be administered cautiously and responsibly without delusions of risk-free treatment.

Published on April 5, 2009 in Medicine