Friday, April 20, 2012

PAT (Pharmacological Aversion Treatment) for the People?

       One segment of the population among whom substance abuse and dependence is a particularly salient problem is that of federal prisoners. Indeed, recent figures indicate that some 59.6% of federal prisoners are incarcerated due to drug-related offenses (Schaffer). Their continued upkeep, including exorbitantly high expenditures for security and medical care, comes as an enormous burden upon both the prison system and the wallets of taxpayers. (R.E. Geiselman, class lecture, January 10, 2012). Perhaps one of the most frustrating aspects of the situation is the fact that, following release, some 70% of these individuals reoffend and subsequently find themselves once again incarcerated within the dreary walls of the prison from which they had so recently been discharged (R.E. Geiselman, class lecture, February 2, 2012).
       There are many reasons for this astronomically high rate of recidivism, including the fact that prisoners are freed with little more than the clothes on their backs and $200-something dollars in their pocket, often right back into the community from which they came, complete with the same gang members, drug suppliers, drug customers, drinking buddies, fellow drug users, etc., as before. As if the environmental cues alone were insufficient for catapulting a newly-released offender into relapse, prisoners are also limited in their efforts to better their lives by stringent and unforgiving external constraints, including the fact that they cannot legally apply for a job without notifying a potential employer that they are a convicted felon (failure to do so is a felony in and of itself), and the like (R.E. Geiselman, class lecture, March 8, 2012). It seems that the cards are indeed very much stacked against newly-released convicts- and that is exactly why it is essential to intervene  among members of this group, not only to aid them in breaking their current cycle of dependence, but also to strengthen their resolve and coping skills for when they are released back into society and find themselves once again confronted with all the environmental cues that accompanied and reinforced their previous drug habit.
       A highly effective form of behavioral treatment for substance abuse which might serve this purpose particularly well is that of "Aversion Treatment" or "Aversion Conditioning." This type of therapy relies upon the principles of classical conditioning to cement a relationship (in the mind of a patient undergoing treatment) between the ingestion of a particular drug of abuse and symptoms of nausea and illness (Howard, 2001, p.561). Aversion treatment operates upon the same principles described by Domjan (2009) in relation to taste aversion conditioning, but as applied in a different context. Results of taste aversion conditioning studies performed by Capaldi, Hunter, & Lin, and also by Ramirez [as cited by Domjan (2009)], "A conditioned taste aversion may be learned if ingestion of a novel flavor is followed by an aversive consequence such as indigestion or food poisoning. In contrast, a taste preference may be learned if a flavor is paired with nutritional repletion or other positive consequences" (Domjan, 2009, p. 80-81). The fact that taste aversions found in humans are also the result of Pavlovian conditioning has been established by Scalera (2002) (as cited by Domjan, 2009). Two findings in regard to conditioned taste aversions are particularly significant- first, that "... a flavor-illness experience can produce a conditioned aversion in just one trial, and the learning can occur even if the illness is delayed several hours after ingestion of food" (Domjan, 2009, p. 81) and second, that "... food aversion learning can be independent of rational thought processes and can go against a person's conclusions about the causes of their illness" (Domjan, 2009, p.81). These findings are significant in that they correlate with separate findings more specifically related to the Pharmacological Aversion Treatment for alcohol dependence pioneered by Howard (2001).
       According to Elkins (as cited in Howard, 2001), "taste aversion conditioning, the process by which  alcohol aversions are established, is a phylogenetically old and highly efficient form of learning" (Howard, 2001, p. 562). As Howard goes on to explain, the results of the more than 1300 studies on human taste aversion conditioning performed since 1985 (Riley and Tuck, 1985, as cited by Howard, 2001), indicate that "(a) taste aversions can be established to highly familiar substances through repeated conditioning trials and discrimination training [in the context of classical conditioning, "discrimination" refers to "a procedure in which one stimulus (the CS+) is paired with the unconditioned stimulus on some trials and and another stimulus (the CS-) is presented without the unconditioned stimulus on other trials. As a result of this procedure the CS+ comes to elicit a conditioned response and the CS- comes to inhibit this response," (Domjan, 2009, p. 297)] (b) cognitive mediation is not necessary for the formation of taste aversions and (c) conditioned taste aversions are often highly resistant to extinction," (Howard, 2001, p. 562).
       The fact that Pharmacological Aversion Treatment [an adaptation of taste aversion conditioning used by Howard (2001) to establish an aversion to the taste and smell of alcohol in a group of hospitalized substance abuse patients] can be learned relatively quickly, following as little as one trial (although in Howard's study, five trials were used), and the fact that the results are at least relatively long-lasting, as well as the fact that, since the process of establishing taste aversions seems to be ingrained in the human psyche and  does not seem particularly dependent upon higher cognitive processes (Howard, 2001), makes it a good option for the treatment of alcohol addiction (and perhaps other substance abuse disorders) in the prison setting, where a shorter length of treatment, (and the cost savings that come with this) might make it an appealing choice for lawmakers and taxpayers alike, while the fact that the process can operate relatively independently of higher thought processes allows it to get around the problems with administration of psychotherapy within the prison setting cited by Robert G. Slater (former acting chief psychiatrist of California State Prison, San Quentin), including his assertion that the unbearable stress imposed upon the human psyche by the constant, unrelenting and deafening noise, as well as the constant threat of being severely physically harmed inherent to the prison setting makes effective psychotherapy impossible, and that, in fact, perhaps the best that can be done for people within the system is to provide them with anxiolytics (to lower their anxiety levels) as well as creative outlets for their feelings (such as classes and involvement in arts-and-crafts activities), and to avoid harming them further while they await their date of release (Slater, 1986); since the effectiveness of Pharmacological Aversion Therapy is rooted in human evolution and the ease with which the human brain is hard-wired to make connections between particular evolutionarily-significant pairs of stimuli (i.e., "consumables" and "gastrointestinal distress that results in severe nausea and vomiting" (Howard, 2001, p. 562)). Furthermore, the fact that higher-level thought processes are not deemed essential to the effectiveness of this treatment might make it easier to standardize and administer than the Cognitive Behavioral Therapy traditionally used in such cases, since, because Cognitive Behavioral Therapy generally focuses upon changing maladaptive cognitions, as well as behaviors (Carroll & Onken, 2005), it's effectiveness is more likely to be dependent upon the skill level of the person administering it (and their ability to assist clients with the process of gaining insight into their difficulties) whereas the effectiveness of Pharmacological Aversion Therapy appears to be inherent in its biological bases, with the result that (if proper procedures for its administration are followed) there should be much less inter-therapist variability and variation in its resulting effectiveness.
        In Howard's (2001) study of Pharmacological Aversion Therapy for alcohol abuse, this type of therapy was given to eighty-two hospitalized alcoholics. In this case, treatment consisted of five Pharmacological Aversion Therapy treatments, delivered (following the obtainment of informed consent) over a ten day period. While participants in this study completed numerous physiological as well as psychological tests (measuring everything from heart rate to their current, self-perceived appetite for alcohol and their self-perceived ability to resist ingesting it), the essential "treatment" in this study consisted of the participants being taken to a treatment room in which the shelves were lined with empty containers from a variety of alcoholic beverages, and where there were advertisements featuring various brands of alcohol on the walls. In this setting, one of the medical staff administering the treatment (either a doctor or a nurse) would pour the participant a glass of the type of alcohol they most liked to pursue, mixing it with an equal amount of warm water (the purpose of the warm water was to enhance the smell and taste of the alcoholic beverage). During initial trials, participants were then encouraged to have contact with the alcohol through smelling it and taking it into their mouth and swishing it around, but to stop short of swallowing it; during later trials, participants were encouraged to actually swallow the alcoholic beverage (although, because vomiting was induced soon after the alcohol was consumed, little alcohol was actually absorbed into the bloodstream). After each such session (a "session" generally lasted between 20 and 30 minutes), the participant was allowed to return to their hospital room. Approximately 30 minutes later and in this new location, the participant was served with their preferred alcoholic beverage- but this time, it contained "oral emitine or tartar emitic" (Howard, 2001, p. 567)- drugs specifically designed to make participants vomit between 5 and 8 minutes following their administration  (it was the relationship between the administration of this vomiting-inducing drug and the taste, smell, and consumption of alcohol that the procedure of the study was designed to reinforce). Furthermore, while the initial treatment of participants (during the first trial of the study) involved administering to participants 4 servings of their alcoholic beverage of choice (the specific type of alcohol they had previously been addicted to), later trials involved administering many different types of alcoholic beverages to the participants, in order to enable them to "generalize the conditioned aversion to a range of alcoholic flavors" (Howard, 2001, p. 567). (Howard, 2001).
       The results of the study, particularly given it's short duration and limited number of trials, (as you will remember, Domjan (2009) also stated that "... a flavor-illness experience can produce a conditioned aversion in just one trial" (Domjan, 2009, p. 81)), are impressive. For instance, prior to treatment, participants, (to whom a measure called the "Alcohol Expectancy Questionnaire" (Howard, 2001, p. 567) was administered), "endorsed an average of 65.9 positive alcohol-related outcome expectancies; the mean number of posttreatment positive outcome expectancies was 35.0" (Howard, 2001, p. 574). With t=-12.2 and a p-value of p<.001 (Howard, 2001, p.567) , such results are statistically significant. Furthermore, on another measure, the "Situational Confidence Questionnaire" (Howard, 2001, p. 567), designed to measure participants confidence that they would be able to resist cues that might, if they failed to have enough self-control to resist them, induce participants to return to their previous drug-taking habit, the "mean participant pretreatment SCQ score was 105.5, compared to a posttreatment score of 198.2 (t= 19.8, p<.001)" (Howard, 2001, p. 567). Thus, it is readily apparent that "confidence that abstinence could be maintained in the face of high-risk situations for relapse increased substantially following PAT" (Howard, 2001, p. 567).
       While self-perceived "self-efficacy" in resisting the urge to return to previous patterns of drug abuse might not, at first glance, appear particularly significant in the context of felony drug offenders just getting released from prison and the like, research into the importance of self-efficacy, including Albert Bandura's 1977 paper 'Self-Efficacy: Toward a Unifying Theory of Behavioral Change' (as cited by Cherry, 2012), would indicate otherwise.
       However, as Howard (2009) readily admits, definitive statements about the effectiveness of Pharmacological Aversion Treatment in the treatment of substance abuse disorders cannot be made until larger-scale studies are conducted and the results of the present study are replicated (Howard, 2001).

                                                                      References

1). Carroll, K. M., & Onken, L. S. (2005). Behavioral therapies for drug addiction. The American Journal  of Psychiatry, 162(8), 1452-1460. Retrieved from ajp.psychiatronline.org


2). Cherry, K. (2012). What is self-efficacy?. Retrieved from http://psychology.about.com/od/theoriesofpersonality/a/self_efficacy.htm


3). Domjan, M. (2009). Learning and behavior. (6 ed., pp. 80-81, 297). Belmont, CA: Wadsworth, Cengage Learning.


4). Howard, M. O. (2001). Pharmacological aversion treatment of alcohol dependence.i. production and prediction of conditioned alcohol aversion. The American Journal of Drug and Alcohol Abuse,27(3), 561-585. doi: 10.1081/ADA-100104519

5). Schaffer, C. A. (n.d.). Basic facts about the war on drugs. Retrieved from http://druglibrary.net/schaffer/Library/basicfax.htm


6). Slater, R.  (1986). Psychiatric intervention in an atmosphere of terror. American Journal of Forensic Psychiatry,7(1), 5-12.




1 comment:

  1. Very interesting study. A few comments off the cuff. First, while it's nice to see a large change in self-efficacy ratings, it still requires verification in the context of actual alcohol availability, such as in the prisoner's home environment.

    Second, I wonder how long lasting the treatment would be, even if it proved effective initially. There is a phenomenon we will be covering in class called latent inhibition a.k.a. the CS prexposure effect, by which stimuli to which the subject has had extensive exposure condition more poorly than do novel stimuli.

    Third, in regards to Howard's actual study, I noticed that the ratings the prisoners gave pre and post treatment, though they changed, were not compared to any type of control groups. Perhaps it was the mere exposure to the US, that is, being made ill and inducing vomiting, that resulted in pseudoconditioning. For example, if another group of prisoners were given the US treatment explicitly unpaired with the alcohol ingestion (e.g., on different days), or following ingestion of a different flavor (other than alcohol), and if they still reported a similar change in ratings of alcohol consumption, then the treatment is less likely to be due to an actual conditioned taste aversion than to pseudoconditioning.

    Nevertheless, this is an interesting pilot study that clearly warrants follow up with appropriate designs (i.e., including controls like those discussed above) and with more valid measures of treatment effectiveness (e.g., the likelihood of actually consuming alcohol if given the chance).

    ReplyDelete