Drug instrumentalization: An unrecognized and “adaptive” class of drug users?
Drug instrumentalization is a state phenomenon that refers to momentary reasons for using a drug. It is not indicative of the problems that the individual may or may not have relative to drug use and therefore cannot be used to separate “adaptive” from “non-adaptive” substance users. For example, even an individual with severe alcohol dependence may have a drink just before giving an important presentation at work to calm severe anxiety; an individual with cocaine dependence may use this drug to acquire the necessary energy to complete an important task. Drug instrumentalization exists across all stages of drug use, abuse, and dependence and therefore has no intrinsic value in characterizing a distinct class of drug users.
A second error concerns the use of the term “adaptive,” which has been used almost as a synonym of drug instrumentalization. There are numerous momentary reasons for drug use that promote the attainment of specific goals, but by no means do these elements justify the label “adaptive” (even among non-dependent individuals). To use M&S's own example, alcohol may be used to increase extroversion and therefore improve the likelihood of contact with the opposite sex. Extroversion may be increased, but what about the increased probability of aggression, sexual assault, or at-risk sexual behaviors? In addition to momentary negative consequences, the non-adaptive nature of drug instrumentalization should also be visible in the long term. Through such instrumentalization and based on the same learning and memory mechanisms that M&S cite, would it not be reasonable to assume the individual would increasingly rely on alcohol as a social vehicle, as well as to become increasingly inhibited with the opposite sex in alcohol-free contexts?
Our conclusion is that drug instrumentalization is not useful for a classification of drug users, and it is certainly not windicative of adaptive behavior.
Can we (and should we) promote “successful drug instrumentalization”?
The take-home message of the target article is that drug use is not necessarily problematic in itself and may even be useful for a large segment of the population. A logical consequence of embracing such a viewpoint would be the normalization of drug use or even its encouragement. Although it may be true that increasing the acceptability (and hence availability) of substances may not change the relative proportion of persons who develop addiction among users, it would almost certainly increase the absolute prevalence of addiction because it would increase the base prevalence of use.
Moreover, M&S pay little attention to the very extensive literature documenting diverse biological (e.g., Crabbe Reference Crabbe2002; Goldman et al. Reference Goldman, Oroszi and Ducci2005; Koob & Le Moal Reference Koob and Le Moal2006), psychological (e.g., Belin et al. Reference Belin, Mar, Dalley, Robbins and Everitt2008; Caspi et al. Reference Caspi, Begg, Dickson, Harrington, Langley, Moffitt and Silva1997; Piazza et al. Reference Piazza, Deminière, Le Moal and Simon1989), and environmental (e.g., Grant et al. Reference Grant, Stinson, Hasin, Dawson, Chou and Anderson2004; Swendsen et al. Reference Swendsen, Conway, Degenhardt, Dierker, Glantz, Jin, Merikangas, Sampson and Kessler2009) vulnerabilities to addiction. These risk factors explain why a large portion of regular drug users will develop harmful use behaviors or addiction (Swendsen & Le Moal Reference Swendsen and Le Moal2011). The authors insist that this percentage is small, probably because they refer to epidemiologic estimates of addiction among individuals who have ever used drugs. However, these lifetime estimates are largely influenced by single-episode experimentation, and they are by no means comparable to rates of addiction among regular or frequent drug users (i.e., the very population conceptualized as drug “instrumentalizers”). For example, although “only” 40% of individuals who have ever smoked will develop nicotine dependence (Dierker et al. Reference Dierker, He, Kalaydjian, Swendsen, Degenhardt, Glantz, Conway, Anthony, Chiu WR Sampson, Kessler and Merikangas2008), the majority of individuals who smoke at least once a week will indeed become dependent. It would be a similar error to believe that most individuals can use heroin, cocaine, or methamphetamine frequently in their daily lives with purely adaptive results and without high rates of addiction.
Finally, there is a flagrant contradiction in the propositions that M&S make for the promotion of “successful” drug instrumentalization. Whether for drug-naïve individuals or for regular drug users, M&S insist on the need for providing education and help in the control of drug use. Why would this be necessary? The response is obvious: The pharmacological qualities of addictive drugs have the capacity to transform drug users, whatever the reason or nature of instrumentalization, into drug addicts. M&S's tacit recognition of this point is in stark contrast to their far bolder message that addictive drug use can have a safe, prolonged, and “adaptive” place in the everyday lives of large sections of the population. It would be a serious mistake to accept this latter framework over the former reality. The price to pay for society in helping individuals find other ways to function other than by using drugs cannot be compared to the price that would be paid by conceptualizing drug use as being a normal and adaptive part of daily life.
In summary, we have argued for why the concept of drug instrumentalization has limited value from the standpoint of nosology, for why it should not be universally viewed as “adaptive,” and for why it has dangerous implications for drug policy and public health efforts.
In their target article, Müller and Schumann (M&S) propose a “new neurobiological framework” for non-addictive drug use whereby people use psychoactive drugs to better perform specific behaviors that are relevant for their own “fitness.” This concept, referred to as drug instrumentalization, is viewed as adaptive; and M&S present it as a reality that the scientific literature and policy makers have largely ignored because of their fears of promoting addiction. The vast majority of M&S's article is composed of a review of the literature of already well-documented facts. Unfortunately, M&S accord very little effort in: (1) defending the validity of this concept as a stable difference between “adaptive” drug users and those who develop addiction; and (2) demonstrating the benefits of promoting “successful” drug instrumentalization among potential or actual drug users. It is these two points alone that constitute the novel contributions of this target article. We contest both points based on the arguments presented below.
Drug instrumentalization: An unrecognized and “adaptive” class of drug users?
Drug instrumentalization is a state phenomenon that refers to momentary reasons for using a drug. It is not indicative of the problems that the individual may or may not have relative to drug use and therefore cannot be used to separate “adaptive” from “non-adaptive” substance users. For example, even an individual with severe alcohol dependence may have a drink just before giving an important presentation at work to calm severe anxiety; an individual with cocaine dependence may use this drug to acquire the necessary energy to complete an important task. Drug instrumentalization exists across all stages of drug use, abuse, and dependence and therefore has no intrinsic value in characterizing a distinct class of drug users.
A second error concerns the use of the term “adaptive,” which has been used almost as a synonym of drug instrumentalization. There are numerous momentary reasons for drug use that promote the attainment of specific goals, but by no means do these elements justify the label “adaptive” (even among non-dependent individuals). To use M&S's own example, alcohol may be used to increase extroversion and therefore improve the likelihood of contact with the opposite sex. Extroversion may be increased, but what about the increased probability of aggression, sexual assault, or at-risk sexual behaviors? In addition to momentary negative consequences, the non-adaptive nature of drug instrumentalization should also be visible in the long term. Through such instrumentalization and based on the same learning and memory mechanisms that M&S cite, would it not be reasonable to assume the individual would increasingly rely on alcohol as a social vehicle, as well as to become increasingly inhibited with the opposite sex in alcohol-free contexts?
Our conclusion is that drug instrumentalization is not useful for a classification of drug users, and it is certainly not windicative of adaptive behavior.
Can we (and should we) promote “successful drug instrumentalization”?
The take-home message of the target article is that drug use is not necessarily problematic in itself and may even be useful for a large segment of the population. A logical consequence of embracing such a viewpoint would be the normalization of drug use or even its encouragement. Although it may be true that increasing the acceptability (and hence availability) of substances may not change the relative proportion of persons who develop addiction among users, it would almost certainly increase the absolute prevalence of addiction because it would increase the base prevalence of use.
Moreover, M&S pay little attention to the very extensive literature documenting diverse biological (e.g., Crabbe Reference Crabbe2002; Goldman et al. Reference Goldman, Oroszi and Ducci2005; Koob & Le Moal Reference Koob and Le Moal2006), psychological (e.g., Belin et al. Reference Belin, Mar, Dalley, Robbins and Everitt2008; Caspi et al. Reference Caspi, Begg, Dickson, Harrington, Langley, Moffitt and Silva1997; Piazza et al. Reference Piazza, Deminière, Le Moal and Simon1989), and environmental (e.g., Grant et al. Reference Grant, Stinson, Hasin, Dawson, Chou and Anderson2004; Swendsen et al. Reference Swendsen, Conway, Degenhardt, Dierker, Glantz, Jin, Merikangas, Sampson and Kessler2009) vulnerabilities to addiction. These risk factors explain why a large portion of regular drug users will develop harmful use behaviors or addiction (Swendsen & Le Moal Reference Swendsen and Le Moal2011). The authors insist that this percentage is small, probably because they refer to epidemiologic estimates of addiction among individuals who have ever used drugs. However, these lifetime estimates are largely influenced by single-episode experimentation, and they are by no means comparable to rates of addiction among regular or frequent drug users (i.e., the very population conceptualized as drug “instrumentalizers”). For example, although “only” 40% of individuals who have ever smoked will develop nicotine dependence (Dierker et al. Reference Dierker, He, Kalaydjian, Swendsen, Degenhardt, Glantz, Conway, Anthony, Chiu WR Sampson, Kessler and Merikangas2008), the majority of individuals who smoke at least once a week will indeed become dependent. It would be a similar error to believe that most individuals can use heroin, cocaine, or methamphetamine frequently in their daily lives with purely adaptive results and without high rates of addiction.
Finally, there is a flagrant contradiction in the propositions that M&S make for the promotion of “successful” drug instrumentalization. Whether for drug-naïve individuals or for regular drug users, M&S insist on the need for providing education and help in the control of drug use. Why would this be necessary? The response is obvious: The pharmacological qualities of addictive drugs have the capacity to transform drug users, whatever the reason or nature of instrumentalization, into drug addicts. M&S's tacit recognition of this point is in stark contrast to their far bolder message that addictive drug use can have a safe, prolonged, and “adaptive” place in the everyday lives of large sections of the population. It would be a serious mistake to accept this latter framework over the former reality. The price to pay for society in helping individuals find other ways to function other than by using drugs cannot be compared to the price that would be paid by conceptualizing drug use as being a normal and adaptive part of daily life.
In summary, we have argued for why the concept of drug instrumentalization has limited value from the standpoint of nosology, for why it should not be universally viewed as “adaptive,” and for why it has dangerous implications for drug policy and public health efforts.