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Sunday, June 16, 2019

Psychological therapies and amphetamine and methamphetamine dependence


Evidence-based cognitive-behavioral and behavioral treatments for drug dependence

By: Tara M. Neavins, Caroline J. Easton, Janet Brotchie and Kathleen M. Carroll

Overview

The purpose of empirical validation of psychological therapies is to identify effective treatments that assist clinicians in delivering appropriate therapies (Chambless et al., 1996; Chambless et al., 1998). In general, this review focuses on interventions classified as ‘empirically validated’ or ‘likely to be efficacious’. To be considered empirically validated, it is necessary that a given treatment demonstrate efficacy in at least two randomized controlled trials (RCTs (McGovern & Carroll, 2003)). Included studies should be methodologically sound and incorporate features such as treatment manuals, random assignment to targeted and appropriate control and treatment conditions, and use validated measures. Moreover, a treatment’s efficacy should be confirmed by at least two independent investigation teams. In contrast, to be considered ‘probably efficacious’, a treatment’s efficacy must be confirmed by at least two positive randomized clinical trials with a waiting list control group, a small series of single case experiments, or one or more experiments meeting criteria for empirical validation but not by independent teams. Although this framework has generated considerable controversy, this model afforded a standard by which to compare treatments (McGovern & Carroll, 2003).

Psychological therapies and amphetamine and methamphetamine dependence

Given the relative ease with which amphetamines and methamphetamines can be manufactured and the minimal cost involved in doing so, it is not surprising that amphetamine and methamphetamine dependence are commonplace (World Health Organization, 2001). Despite the prevalence of amphetamine and methamphetamine dependence, no empirically validated pharmacological and only one empirically validated behavioral treatment of methamphetamine dependence currently exists (Rawson et al., 2004; World Health Organization, 2001).


Baker et al. (2001) conducted a randomized controlled trial of brief psychological treatments for regular amphetamine users (individuals who used one or more times per month). Amphetamine users were assigned to one of three conditions:

(1) four sessions of CBT (including Motivational Interviewing [MI], relapse-prevention, skills training, coping with cravings) plus a self-help booklet,
(2) two sessions of CBT (including a motivational interview and skills training) plus a self-help booklet, or
(3) an assessment and a self-help booklet.

Overall, all participants, irrespective of treatment assignment, reduced their amphetamine use throughout the course of the study. Participants in either of the CBT conditions reported more than two times less daily amphetamine use than participants in the self-help booklet (control) condition. In addition, at 6-month follow-up, a significantly greater number of individuals in the CBT conditions were abstinent from amphetamine use as compared with the control condition.

Although efficacious behavioral treatments for amphetamine dependence need considerable investigation, the Matrix Model (a manualized, intensive, 16-session treatment which broadens CBT by supplementing it with family education, drug education, and Alcoholics or Narcotics Anonymous meetings) offers some promise for methamphetamine abuse and dependence (Huber et al., 1997; Rawson et al., 2004) after successful use with cocaine addicts (Rawson et al., 1991, 1995). In the biggest randomized clinical trial in existence for methamphetamine dependence, Rawson et al. (2004) randomized 978 methamphetamine users at eight sites to one of two outpatient treatment conditions:

(1) the Matrix Model or
(2) a control condition (standard treatment).

The superiority of the Matrix Model, as evidenced by a higher percentage of treatment sessions attended, longer involvement in treatment, greater number of methamphetamine-negative urines, and more days of methamphetamine abstinence, was observed during the treatment phase. However, patients showed less drug use and greater functioning in both conditions when the treatment ended and at 6- month follow-up. That is, the Matrix Model was not significantly better than standard treatment at the end of treatment or at 6-month follow-up.

Low-cost contingency management of amphetamine and methamphetamine dependence Petry et al. (2005) randomly assigned 415, outpatient substance abuse treatment, methamphetamine (or cocaine) users to either standard treatment or contingency management (CM; based on providing substance-free urine specimens) and standard treatment. This study was unique in that it was run across eight community-based agencies. Participants in the CM plus standard treatment condition stayed in treatment longer, attended more counseling sessions, produced more substance-free urine specimens (in terms of alcohol, cocaine, and methamphetamines), and achieved abstinence for longer periods of the 12-week study. Surprisingly, the two groups did not differ in terms of the percentage of urine specimens which were positive for substances. These researchers found this treatment to be very cost-effective and noted that the average amount spent on incentives per individual was only $203.

Building upon the earlier work of Petry et al. (2005), Peirce et al. (2006) conducted a multi-site investigation at six methadone maintenance treatment programmes in various community settings. A total of 388 participants, over 80% of whom were abusing or dependent upon cocaine, methamphetamines, and/or amphetamines (as well as heroin) were randomized either to CM (based on submitting alcohol-free breathalyzer readings and urine samples free of cocaine, methamphetamines, or amphetamines) or a non-CM (standard treatment) condition during the 12-week study. Among the most significant study findings, Peirce et al. observed that the CM group was two times more apt as the standard treatment condition to produce alcohol-free and stimulant-free (cocaine, methamphetamines, and amphetamines) urine specimens. Overall, CM participants had 11 times greater chance of remaining abstinent from stimulants than standard treatment participants. No differences were found between the two groups with regard to remaining in the study or attending sessions. Furthermore, the average cost per participant (i.e. $120/day) was approximately 40% less than that found by Petry et al. (2005).

References

Peter Tyrer and Kenneth R. Silk, Cambridge Textbook of Effective Treatments in Psychiatry, Cambridge University Press 2008.

Read Also

An Introduction and Conclusions to Psychological treatments of alcohol use disorders
Educational interventions for alcohol use disorders
Complex interventions for alcohol use disorders
Alcoholics Anonymous
The Minnesota model of care for alcohol use disorders
Therapeutic communities for alcohol use disorders
Combined pharmacotherapy and psychotherapy for alcohol use disorders
An Introduction to Pharmacotherapy of alcohol misuse, dependence and withdrawal
Treatment of sedative-hypnotic dependence
Treatment of nicotine dependence
Treatment of co-occurring psychiatric and substance use disorders

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